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Drilling-based measuring method for the c-φ parameter of rock and its field application 被引量:2
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作者 Bei Jiang Fenglin Ma +5 位作者 Qi Wang Hongke Gao Dahu Zhai Yusong Deng Chuanjie Xu Liangdi Yao 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2024年第1期65-76,共12页
The technology of drilling tests makes it possible to obtain the strength parameter of rock accurately in situ. In this paper, a new rock cutting analysis model that considers the influence of the rock crushing zone(R... The technology of drilling tests makes it possible to obtain the strength parameter of rock accurately in situ. In this paper, a new rock cutting analysis model that considers the influence of the rock crushing zone(RCZ) is built. The formula for an ultimate cutting force is established based on the limit equilibrium principle. The relationship between digital drilling parameters(DDP) and the c-φ parameter(DDP-cφ formula, where c refers to the cohesion and φ refers to the internal friction angle) is derived, and the response of drilling parameters and cutting ratio to the strength parameters is analyzed. The drillingbased measuring method for the c-φ parameter of rock is constructed. The laboratory verification test is then completed, and the difference in results between the drilling test and the compression test is less than 6%. On this basis, in-situ rock drilling tests in a traffic tunnel and a coal mine roadway are carried out, and the strength parameters of the surrounding rock are effectively tested. The average difference ratio of the results is less than 11%, which verifies the effectiveness of the proposed method for obtaining the strength parameters based on digital drilling. This study provides methodological support for field testing of rock strength parameters. 展开更多
关键词 Digital drilling Rock crushing zone c-u parameter Measurement method Field application
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A real-time intelligent lithology identification method based on a dynamic felling strategy weighted random forest algorithm
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作者 Tie Yan Rui Xu +2 位作者 Shi-Hui Sun Zhao-Kai Hou Jin-Yu Feng 《Petroleum Science》 SCIE EI CAS CSCD 2024年第2期1135-1148,共14页
Real-time intelligent lithology identification while drilling is vital to realizing downhole closed-loop drilling. The complex and changeable geological environment in the drilling makes lithology identification face ... Real-time intelligent lithology identification while drilling is vital to realizing downhole closed-loop drilling. The complex and changeable geological environment in the drilling makes lithology identification face many challenges. This paper studies the problems of difficult feature information extraction,low precision of thin-layer identification and limited applicability of the model in intelligent lithologic identification. The author tries to improve the comprehensive performance of the lithology identification model from three aspects: data feature extraction, class balance, and model design. A new real-time intelligent lithology identification model of dynamic felling strategy weighted random forest algorithm(DFW-RF) is proposed. According to the feature selection results, gamma ray and 2 MHz phase resistivity are the logging while drilling(LWD) parameters that significantly influence lithology identification. The comprehensive performance of the DFW-RF lithology identification model has been verified in the application of 3 wells in different areas. By comparing the prediction results of five typical lithology identification algorithms, the DFW-RF model has a higher lithology identification accuracy rate and F1 score. This model improves the identification accuracy of thin-layer lithology and is effective and feasible in different geological environments. The DFW-RF model plays a truly efficient role in the realtime intelligent identification of lithologic information in closed-loop drilling and has greater applicability, which is worthy of being widely used in logging interpretation. 展开更多
关键词 Intelligent drilling Closed-loop drilling Lithology identification Random forest algorithm Feature extraction
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In situ digital testing method for quality assessment of soft soil improvement with polyurethane
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作者 X.F.Wang C.J.Wang +2 位作者 W.V.Yue Z.J.Zhang Z.Q.Yue 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第5期1732-1748,共17页
This study purposes an in situ testing method on quality assessment of soil improvement.Factual drilling data includes the spatial distribution and in situ strength of untreated and treated soil along three different ... This study purposes an in situ testing method on quality assessment of soil improvement.Factual drilling data includes the spatial distribution and in situ strength of untreated and treated soil along three different drillholes measured by on-site drilling monitoring method.These factual drilling data can characterize the degree of soil improvement by penetration injection with permeable polyurethane.Result from on-site drilling monitoring shows that the linear zones represent constant drilling speeds shown in the plot of drill bit advancement vs.net drilling time,which indicates the spatial distributions of soil profile.The soil profile at the study site is composed of four layers,which includes fill,untreated silty clay,treated silty clay,and mucky soil.The results of soil profile are verified by the parallel site loggings.The constant drilling speeds profile the coring-resistant strength of drilled soils.By comparing with the untreated silty clay,the constant drilling speeds of the treated silty clay have been decreased by 13.0-62.8%.Two drilling-speed-based indices of 61.2%and 65.6%are proposed to assess the decreased average drilling speed and the increased in situ strength of treated silty clay.Laboratory tests,i.e.uniaxial compressive strength(UCS)test,have been performed with core sample to investigate and characterize in situ strength by comparing that with drilling speeds.Results show that the average predicted strengths of treated silty clay are 2.4-6.9 times higher than the average measured strength of untreated silty clay.The UCS-based indices of 374.5%and 344.2%verified the quality assessment(QA)results by this new in situ method.This method provides a cost-effective tool for quality assessment of soil improvement by utilizing the digital drilling data. 展开更多
关键词 Drilling process monitoring system Hydraulic rotary drilling process Constant drilling speed Soil improvement Quality assessment
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The Conversion of Non-Dispersed Polymers into Low-Potassium Anti-Collapse Drilling Fluids
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作者 Hao Hu Jian Guan +2 位作者 Shanfa Tang Jialuo Rong Yuanpeng Cheng 《Fluid Dynamics & Materials Processing》 EI 2024年第2期325-335,共11页
Different drillingfluid systems are designed according to mineral composition,lithology and wellbore stability of different strata.In the present study,the conversion of a non-dispersed polymer drillingfluid into a low ... Different drillingfluid systems are designed according to mineral composition,lithology and wellbore stability of different strata.In the present study,the conversion of a non-dispersed polymer drillingfluid into a low potas-sium anti-collapsing drillingfluid is investigated.Since the two drillingfluids belong to completely different types,the key to this conversion is represented by new inhibitors,dispersants and water-loss agents by which a non-dispersed drillingfluid can be turned into a dispersed drillingfluid while ensuring wellbore stability and reason-able rheology(carrying sand—inhibiting cuttings dispersion).In particular,the(QYZ-1)inhibitors and(FSJSS-2)dispersants are used.The former can inhibit the hydration expansion capacity of clay,reduce the dynamic shear force and weaken the viscosity;the latter can improve the sealing effect and reduce thefiltrate loss.The results have shown that after adding a reasonable proportion of these substances(QYZ-1:FSJSS-2)to the non-dispersed polymer drillingfluid,while the apparent viscosity,plastic viscosity,structural viscosity andfluidity index under-went almost negligible changes,the dynamic plastic ratio increased,and thefiltration loss decreased significantly,thereby indicating good compatibility.According to the tests(conducted in the Leijia area),the density was 1.293 g/cm3,and after standing for 24 h,the SF(static settlement factor)was 0.51.Moreover,thefiltration loss was reduced to 4.0 mL,the rolling recovery rate reached 96.92%,with excellent plugging and anti-collapse performances. 展开更多
关键词 Non-dispersed polymer drilling fluid low potassium anti-collapsing drilling fluid drilling fluid conversion drilling fluid reuse filter vector
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Digital monitoring of rotary-percussive drilling with down-the-hole hammer for profiling weathered granitic ground
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作者 Wendal Victor Yue Siyuan Wu +2 位作者 Manchao He Yafei Qiao Zhongqi Quentin Yue 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第5期1615-1636,共22页
Rock and geotechnical engineering investigations involve drilling holes in ground with or without retrieving soil and rock samples to construct the subsurface ground profile.On the basis of an actual soil nailing dril... Rock and geotechnical engineering investigations involve drilling holes in ground with or without retrieving soil and rock samples to construct the subsurface ground profile.On the basis of an actual soil nailing drilling for a slope stability project in Hong Kong,this paper further develops the drilling process monitoring(DPM)method for digitally profiling the subsurface geomaterials of weathered granitic rocks using a compressed airflow driven percussive-rotary drilling machine with down-the-hole(DTH)hammer.Seven transducers are installed on the drilling machine and record the chuck displacement,DTH rotational speed,and five pressures from five compressed airflows in real-time series.The mechanism and operations of the drilling machine are elaborated in detail,which is essential for understanding and evaluating the drilling data.A MATLAB program is developed to automatically filter the recorded drilling data in time series and classify them into different drilling processes in sub-time series.These processes include penetration,push-in with or without rod,pull-back with or without rod,rod-tightening and rod-untightening.The drilling data are further reconstructed to plot the curve of drill-bit depth versus the net drilling time along each of the six drillholes.Each curve is found to contain multiple linear segments with a constant penetration rate,which implies a zone of homogenous geomaterial with different weathering grades.The effect from fluctuation of the applied pressures is evaluated quantitatively.Detailed analyses are presented for accurately assess and verify the underground profiling and strength in weathered granitic rock,which provided the basis of using DPM method to confidently assess drilling measurements to interpret the subsurface profile in real time. 展开更多
关键词 Drilling process monitoring(DPM) Down-the-hole(DTH)hammer Percussive-rotary drilling Weathering granitic rocks
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A novel responsive stabilizing Janus nanosilica as a nanoplugging agent in water-based drilling fluids for exploiting hostile shale environments
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作者 Alain Pierre Tchameni Lv-Yan Zhuo +5 位作者 Lesly Dasilva Wandji Djouonkep Robert Dery Nagre Lu-Xin Chen Lin Zhao Chao Ma Bin-Qiang Xie 《Petroleum Science》 SCIE EI CAS CSCD 2024年第2期1190-1210,共21页
Thermo-responsive nanocomposites have recently emerged as potential nanoplugging agents for shale stabilization in high-temperature water-based drilling fluids(WBDFs). However, their inhibitory properties have not bee... Thermo-responsive nanocomposites have recently emerged as potential nanoplugging agents for shale stabilization in high-temperature water-based drilling fluids(WBDFs). However, their inhibitory properties have not been very effective in high-temperature drilling operations. Thermo-responsive Janus nanocomposites are expected to strongly interact with clay particles from the inward hemisphere of nanomaterials, which drive the establishment of a tighter hydrophobic membrane over the shale surface at the outward hemisphere under geothermal conditions for shale stabilization. This work combines the synergistic benefits of thermo-responsive and zwitterionic nanomaterials to synchronously enhance the chemical inhibitions and plugging performances in shale under harsh conditions. A novel thermoresponsive Janus nanosilica(TRJS) exhibiting zwitterionic character was synthesized, characterized,and assessed as shale stabilizer for WBDFs at high temperatures. Compared to pristine nanosilica(Si NP)and symmetrical thermo-responsive nanosilica(TRS), TRJS exhibited anti-polyelectrolyte behaviour, in which electrolyte ions screened the electrostatic attraction between the charged particles, potentially stabilizing nanomaterial in hostile shaly environments(i.e., up to saturated brine or API brine). Macroscopically, TRJS exhibited higher chemical inhibition than Si NP and TRS in brine, prompting a better capability to control pressure penetration. TRJS adsorbed onto the clay surface via chemisorption and hydrogen bonding, and the interactions became substantial in brine, according to the results of electrophoretic mobility, surface wettability, and X-ray diffraction. Thus, contributing to the firm trapping of TRJS into the nanopore structure of the shale, triggering the formation of a tight hydrophobic membrane over the shale surface from the outward hemisphere. The addition of TRJS into WBDF had no deleterious effect on fluid properties after hot-treatment at 190℃, implying that TRJS could find potential use as a shale stabilizer in WBDFs in hostile environments. 展开更多
关键词 Janus nanosilica Thermo-responsive copolymer Anti-polyelectrolyte effect Shale stabilizer Inhibition Plugging Drilling fluid
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Chemical modification of barite for improving the performance of weighting materials for water-based drilling fluids
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作者 Li-Li Yang Ze-Yu Liu +3 位作者 Shi-bo Wang Xian-Bo He Guan-Cheng Jiang Jie Zhang 《Petroleum Science》 SCIE EI CAS CSCD 2024年第1期551-566,共16页
With increasing drilling depth and large dosage of weighting materials,drilling fluids with high solid content are characterized by poor stability,high viscosity,large water loss,and thick mud cake,easier leading to r... With increasing drilling depth and large dosage of weighting materials,drilling fluids with high solid content are characterized by poor stability,high viscosity,large water loss,and thick mud cake,easier leading to reservoir damage and wellbore instability.In this paper,micronized barite(MB)was modified(mMB)by grafting with hydrophilic polymer onto the surface through the free radical polymerization to displace conventional API barite partly.The suspension stability of water-based drilling fluids(WBDFs)weighted with API barite:mMB=2:1 in 600 g was significantly enhanced compared with that with API barite/WBDFs,exhibiting the static sag factor within 0.54 and the whole stability index of 2.The viscosity and yield point reached the minimum,with a reduction of more than 40%compared with API barite only at the same density.Through multi-stage filling and dense accumulation of weighting materials and clays,filtration loss was decreased,mud cake quality was improved,and simultaneously it had great reservoir protection performance,and the permeability recovery rate reached 87%.In addition,it also effectively improved the lubricity of WBDFs.The sticking coefficient of mud cake was reduced by 53.4%,and the friction coefficient was 0.2603.Therefore,mMB can serve as a versatile additive to control the density,rheology,filtration,and stability of WBDFs weighted with API barite,thus regulating comprehensive performance and achieving reservoir protection capacity.This work opened up a new path for the productive drilling of extremely deep and intricate wells by providing an efficient method for managing the performance of high-density WBDFs. 展开更多
关键词 Drilling fluids Weighting materials Filtration control Reservoir protection Stability property
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Synthetic polymers:A review of applications in drilling fluids
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作者 Shadfar Davoodi Mohammed Al-Shargabi +2 位作者 David A.Wood Valeriy S.Rukavishnikov Konstantin M.Minaev 《Petroleum Science》 SCIE EI CAS CSCD 2024年第1期475-518,共44页
With the growth of deep drilling and the complexity of the well profile,the requirements for a more complete and efficient exploitation of productive formations increase,which increases the risk of various complicatio... With the growth of deep drilling and the complexity of the well profile,the requirements for a more complete and efficient exploitation of productive formations increase,which increases the risk of various complications.Currently,reagents based on modified natural polymers(which are naturally occurring compounds)and synthetic polymers(SPs)which are polymeric compounds created industrially,are widely used to prevent emerging complications in the drilling process.However,compared to modified natural polymers,SPs form a family of high-molecular-weight compounds that are fully synthesized by undergoing chemical polymerization reactions.SPs provide substantial flexibility in their design.Moreover,their size and chemical composition can be adjusted to provide properties for nearly all the functional objectives of drilling fluids.They can be classified based on chemical ingredients,type of reaction,and their responses to heating.However,some of SPs,due to their structural characteristics,have a high cost,a poor temperature and salt resistance in drilling fluids,and degradation begins when the temperature reaches 130℃.These drawbacks prevent SP use in some medium and deep wells.Thus,this review addresses the historical development,the characteristics,manufacturing methods,classification,and the applications of SPs in drilling fluids.The contributions of SPs as additives to drilling fluids to enhance rheology,filtrate generation,carrying of cuttings,fluid lubricity,and clay/shale stability are explained in detail.The mechanisms,impacts,and advances achieved when SPs are added to drilling fluids are also described.The typical challenges encountered by SPs when deployed in drilling fluids and their advantages and drawbacks are also discussed.Economic issues also impact the applications of SPs in drilling fluids.Consequently,the cost of the most relevant SPs,and the monomers used in their synthesis,are assessed.Environmental impacts of SPs when deployed in drilling fluids,and their manufacturing processes are identified,together with advances in SP-treatment methods aimed at reducing those impacts.Recommendations for required future research addressing SP property and performance gaps are provided. 展开更多
关键词 Synthetic versus natural polymers Nanopolymers Drilling fluid additives LUBRICITY Clay swelling Hole cleaning
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Inverting the rock mass P-wave velocity field ahead of deep buried tunnel face while borehole drilling
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作者 Liu Liu Shaojun Li +5 位作者 Minzong Zheng Dong Wang Minghao Chen Junbo Zhou Tingzhou Yan Zhenming Shi 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2024年第5期681-697,共17页
Imaging the wave velocity field surrounding a borehole while drilling is a promising and urgently needed approach for extending the exploration range of the borehole point.This paper develops a drilling process detect... Imaging the wave velocity field surrounding a borehole while drilling is a promising and urgently needed approach for extending the exploration range of the borehole point.This paper develops a drilling process detection(DPD)system consisting of a multifunctional sensor and a pilot geophone installed at the top of the drilling rod,geophones at the tunnel face,a laser rangefinder,and an onsite computer.A weighted adjoint-state first arrival travel time tomography method is used to invert the P-wave velocity field of rock mass while borehole drilling.A field experiment in the ongoing construction of a deep buried tunnel in southwestern China demonstrated the DPD system and the tomography method.Time-frequency analysis of typical borehole drilling detection data shows that the impact drilling source is a pulse-like seismic exploration wavelet.A velocity field of the rock mass in a triangular area defined by the borehole trajectory and geophone receiving line can be obtained.Both the borehole core and optical image validate the inverted P-wave velocity field.A numerical simulation of a checkerboard benchmark model is used to test the tomography method.The rapid convergence of the misfits and consistent agreement between the inverted and observed travel times validate the P-wave velocity imaging. 展开更多
关键词 Deep buried tunnel Wave velocity field Borehole drilling Tomography Rock mass
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Fracture sealing performance of granular lost circulation materials at elevated temperature:A theoretical and coupled CFD-DEM simulation study
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作者 Chong Lin Qi-Cong Xu +4 位作者 Lie-Xiang Han Gao Li Hai He Hong-Ling Zhou Ji-Ping She 《Petroleum Science》 SCIE EI CAS CSCD 2024年第1期567-581,共15页
Lost circulation is a common downhole problem of drilling in geothermal and high-temperature,high-pressure(HTHP)formations.Lost circulation material(LCM)is a regular preventive and remedial measure for lost circulatio... Lost circulation is a common downhole problem of drilling in geothermal and high-temperature,high-pressure(HTHP)formations.Lost circulation material(LCM)is a regular preventive and remedial measure for lost circulation.However,conventional LCMs seem ineffective in high-temperature formations.This may be due to the changes in the mechanical properties of LCMs and their sealing performance under high-temperature conditions.To understand how high temperature affects the fracture sealing performance of LCMs,we developed a coupled computational fluid dynamics-discrete element method(CFD-DEM)model to simulate the behavior of granular LCMs in fractures.We summarized the literature on the effects of high temperature on the mechanical properties of LCMs and the rheological properties of drilling fluid.We conducted sensitivity analyses to investigate how changing LCM slurry properties affected the fracture sealing efficiency at increasing temperatures.The results show that high temperature reduces the size,strength,and friction coefficient of LCMs as well as the drilling fluid viscosity.Smaller,softer,and less frictional LCM particles have lower bridging probability and slower bridging initiation.Smaller particles tend to form dual-particle bridges rather than single-particle bridges.These result in a deeper,tighter,but unstable sealing zone.Reduced drilling fluid viscosity leads to faster and shallower sealing zones. 展开更多
关键词 Geothermal well drilling HTHP formationLost circulation material CFD-DEM Fracture sealing
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Dynamic Analysis of A Deepwater Drilling Riser with A New Hang-off System
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作者 LI Yan-wei LIU Xiu-quan +3 位作者 WANG Jin-long CHEN Guo-ming CHANG Yuan-jiang SHENG Lei-xiang 《China Ocean Engineering》 SCIE EI CSCD 2024年第1期29-41,共13页
The safety of risers in hang-off states is a vital challenge in offshore oil and gas engineering.A new hang-off system installed on top of risers is proposed for improving the security of risers.This approach leads to... The safety of risers in hang-off states is a vital challenge in offshore oil and gas engineering.A new hang-off system installed on top of risers is proposed for improving the security of risers.This approach leads to a challenging problem:coupling the dynamics of risers with a new hang-off system combined with multiple structures and complex constraints.To accurately analyze the dynamic responses of the coupled system,a coupled dynamic model is established based on the Euler-Bernoulli beam-column theory and penalty function method.A comprehensive analysis method is proposed for coupled dynamic analysis by combining the finite element method and the Newmarkβmethod.An analysis program is also developed in MATLAB for dynamic simulation.The simulation results show that the dynamic performances of the risers at the top part are significantly improved by the new hang-off system,especially the novel design,which includes the centralizer and articulation joint.The bending moment and lateral deformation of the risers at the top part decrease,while the hang-off joint experiences a great bending moment at the bottom of the lateral restraint area which requires particular attention in design and application.The platform navigation speed range under the safety limits of risers expands with the new hang-off system in use. 展开更多
关键词 deepwater drilling riser new hang-off system dynamic analysis finite element method penalty function method
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Formation damage mechanism and control strategy of the compound function of drilling fluid and fracturing fluid in shale reservoirs
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作者 SUN Jinsheng XU Chengyuan +6 位作者 KANG Yili JING Haoran ZHANG Jie YANG Bin YOU Lijun ZHANG Hanshi LONG Yifu 《Petroleum Exploration and Development》 SCIE 2024年第2期430-439,共10页
For the analysis of the formation damage caused by the compound function of drilling fluid and fracturing fluid,the prediction method for dynamic invasion depth of drilling fluid is developed considering the fracture ... For the analysis of the formation damage caused by the compound function of drilling fluid and fracturing fluid,the prediction method for dynamic invasion depth of drilling fluid is developed considering the fracture extension due to shale minerals erosion by oil-based drilling fluid.With the evaluation for the damage of natural and hydraulic fractures caused by mechanical properties weakening of shale fracture surface,fracture closure and rock powder blocking,the formation damage pattern is proposed with consideration of the compound effect of drilling fluid and fracturing fluid.The formation damage mechanism during drilling and completion process in shale reservoir is revealed,and the protection measures are raised.The drilling fluid can deeply invade into the shale formation through natural and induced fractures,erode shale minerals and weaken the mechanical properties of shale during the drilling process.In the process of hydraulic fracturing,the compound effect of drilling fluid and fracturing fluid further weakens the mechanical properties of shale,results in fracture closure and rock powder shedding,and thus induces stress-sensitive damage and solid blocking damage of natural/hydraulic fractures.The damage can yield significant conductivity decrease of fractures,and restrict the high and stable production of shale oil and gas wells.The measures of anti-collapse and anti-blocking to accelerate the drilling of reservoir section,forming chemical membrane to prevent the weakening of the mechanical properties of shale fracture surface,strengthening the plugging of shale fracture and reducing the invasion range of drilling fluid,optimizing fracturing fluid system to protect fracture conductivity are put forward for reservoir protection. 展开更多
关键词 shale oil and gas drilling fluid fracturing fluid stress-sensitive solid blocking formation damage reservoir protection
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A Gel-Based Solidification Technology for Large Fracture Plugging
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作者 Kunjian Wang Ruibin He +3 位作者 Qianhua Liao Kun Xu Wen Wang Kan Chen 《Fluid Dynamics & Materials Processing》 EI 2024年第3期563-578,共16页
Fault fractures usually have large openings and considerable extension. Accordingly, cross-linked gel materials aregenerally considered more suitable plugging agents than water-based gels because the latter often unde... Fault fractures usually have large openings and considerable extension. Accordingly, cross-linked gel materials aregenerally considered more suitable plugging agents than water-based gels because the latter often undergo contaminationvia formation water, which prevents them from being effective over long times. Hence, in this study, aset of oil-based composite gels based on waste grease and epoxy resin has been developed. These materials havebeen observed to possess high compressive strength and resistance to the aforementioned contamination, therebyleading to notable increase in plugging success rate. The compressive strength, thickening time, and resistance toformation water pollution of these gels have been evaluated indoors. The results show that the compressivestrength of the gel can reach 11 MPa;additionally, the related gelation time can be controlled to be more than3 h, thereby providing a safe construction time;Invasion of formation water has a small effect on the gel strengthand does not shorten the thickening time. All considered performance indicators of the oil-based gel confirm itssuitability as a plugging agent for fault fractures. 展开更多
关键词 Drilling loss fault fracture oil-based gel compressive strength gel plugging
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Research on the Method of Heat Preservation and Heating for the Drilling System of Polar Offshore Drilling Platform
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作者 Yingkai Dong Chaohe Chen +2 位作者 Guangyan Jia Lidai Wang Jian Bai 《Energy Engineering》 EI 2024年第5期1173-1193,共21页
This study investigates the heat dissipation mechanism of the insulation layer and other plane insulation layers in the polar drilling rig system.Combining the basic theory of heat transfer with the environmental requ... This study investigates the heat dissipation mechanism of the insulation layer and other plane insulation layers in the polar drilling rig system.Combining the basic theory of heat transfer with the environmental requirements of polar drilling operations and the characteristics of polar drilling processes,we analyze the factors that affect the insulation effect of the drilling rig system.These factors include the thermal conductivity of the insulation material,the thickness of the insulation layer,ambient temperature,and wind speed.We optimize the thermal insulation material of the polar drilling rig system using a steady-state method to measure solid thermal conductivity.By analyzing the distribution of temperature in space after heating,we optimize the distribution and air outlet angle of the heater using Fluent hydrodynamics software.The results demonstrate that under polar conditions,polyisocyanurate with stable thermodynamic properties is selected as the thermal insulation material.The selection of thermal insulation material and thickness significantly affects the thermal insulation effect of the system but has little effect on its heating effect.Moreover,when the air outlet angle of the heater is set to 32.5°,the heating efficiency of the system can be effectively improved.According to heat transfer equations and heat balance theory,we determine that the heating power required for the system to reach 5°C is close to numerical simulation. 展开更多
关键词 Polar drilling drilling system fluid dynamics heat preservation and heating numerical simulation
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A New Heat Transfer Model for Multi-Gradient Drilling with Hollow Sphere Injection
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作者 Jiangshuai Wang Chuchu Cai +3 位作者 Pan Fu Jun Li Hongwei Yang Song Deng 《Fluid Dynamics & Materials Processing》 EI 2024年第3期537-546,共10页
Multi-gradient drilling is a new offshore drilling method.The accurate calculation of the related wellbore temperature is of great significance for the prediction of the gas hydrate formation area and the precise cont... Multi-gradient drilling is a new offshore drilling method.The accurate calculation of the related wellbore temperature is of great significance for the prediction of the gas hydrate formation area and the precise control of the wellbore pressure.In this study,a new heat transfer model is proposed by which the variable mass flow is properly taken into account.Using this model,the effects of the main factors influencing the wellbore temperature are analyzed.The results indicate that at the position where the separation injection device is installed,the temperature increase of the fluid in the drill pipe is mitigated due to the inflow/outflow of hollow spheres,and the temperature drop of the fluid in the annulus also decreases.In addition,a lower separation efficiency of the device,a shallower installation depth and a smaller circulating displacement tend to increase the temperature near the bottom of the annulus,thereby helping to reduce the hydrate generation area and playing a positive role in the prevention and control of hydrates in deepwater drilling. 展开更多
关键词 Multi-gradient drilling wellbore temperature HYDRATE separate injection device variable mass
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Deep-large faults controlling on the distribution of the venting gas hydrate system in the middle of the Qiongdongnan Basin, South China Sea
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作者 Jin-feng Ren Hai-jun Qiu +6 位作者 Zeng-gui Kuang Ting-wei Li Yu-lin He Meng-jie Xu Xiao-xue Wang Hong-fei Lai Jin Liang 《China Geology》 CAS CSCD 2024年第1期36-50,共15页
Many locations with concentrated hydrates at vents have confirmed the presence of abundant thermogenic gas in the middle of the Qiongdongnan Basin(QDNB).However,the impact of deep structures on gasbearing fluids migra... Many locations with concentrated hydrates at vents have confirmed the presence of abundant thermogenic gas in the middle of the Qiongdongnan Basin(QDNB).However,the impact of deep structures on gasbearing fluids migration and gas hydrates distribution in tectonically inactive regions is still unclear.In this study,the authors apply high-resolution 3D seismic and logging while drilling(LWD)data from the middle of the QDNB to investigate the influence of deep-large faults on gas chimneys and preferred gasescape pipes.The findings reveal the following:(1)Two significant deep-large faults,F1 and F2,developed on the edge of the Songnan Low Uplift,control the dominant migration of thermogenic hydrocarbons and determine the initial locations of gas chimneys.(2)The formation of gas chimneys is likely related to fault activation and reactivation.Gas chimney 1 is primarily arises from convergent fluid migration resulting from the intersection of the two faults,while the gas chimney 2 benefits from a steeper fault plane and shorter migration distance of fault F2.(3)Most gas-escape pipes are situated near the apex of the two faults.Their reactivations facilitate free gas flow into the GHSZ and contribute to the formation of fracture‐filling hydrates. 展开更多
关键词 Venting gas hydrates Deep-large faults Gas chimney Gas-escape pipes High-resolution 3D seismic Logging while drilling Qiongdongnan Basin South China Sea
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Spatial structural characteristics of the Deda ancient landslide in the eastern Tibetan Plateau:Insights from Audio-frequency Magnetotellurics and the Microtremor Survey Method
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作者 Zhen-dong Qiu Chang-bao Guo +5 位作者 Yi-ying Zhang Zhi-hua Yang Rui-an Wu Yi-qiu Yan Wen-kai Chen Feng Jin 《China Geology》 CAS CSCD 2024年第2期188-202,共15页
It is of crucial importance to investigate the spatial structures of ancient landslides in the eastern Tibetan Plateau’s alpine canyons as they could provide valuable insights into the evolutionary history of the lan... It is of crucial importance to investigate the spatial structures of ancient landslides in the eastern Tibetan Plateau’s alpine canyons as they could provide valuable insights into the evolutionary history of the landslides and indicate the potential for future reactivation.This study examines the Deda ancient landslide,situated in the Chalong-ranbu fault zone,where creep deformation suggests a complex underground structure.By integrating remote sensing,field surveys,Audio-frequency Magnetotellurics(AMT),and Microtremor Survey Method(MSM)techniques,along with engineering geological drilling for validation,to uncover the landslide’s spatial feature s.The research indicates that a fault is developed in the upper part of the Deda ancient landslide,and the gully divides it into Deda landslide accumulation zoneⅠand Deda landslide accumulation zoneⅡin space.The distinctive geological characteristics detectable by MSM in the shallow subsurface and by AMT in deeper layers.The findings include the identification of two sliding zones in the Deda I landslide,the shallow sliding zone(DD-I-S1)depth is approximately 20 m,and the deep sliding zone(DD-I-S2)depth is 36.2-49.9 m.The sliding zone(DD-Ⅱ-S1)depth of the DedaⅡlandslide is 37.6-43.1 m.A novel MSM-based method for sliding zone identification is proposed,achieving less than 5%discrepancy in depth determination when compared with drilling data.These results provide a valuable reference for the spatial structural analysis of large-deepseated landslides in geologically complex regions like the eastern Tibetan Plateau. 展开更多
关键词 Ancient landslide Remote sensing Audio-frequency Magnetotellurics(AMT) Microtremor Survey Method(MSM) Geological drilling engineering Spatial structure Tibetan Plateau Geological hazard survey engineering
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Two stages power generation test of the hot dry rock exploration and production demonstration project in the Gonghe Basin,northeastern Qinghai-Tibet plateau,China
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作者 Er-yong Zhang Dong-guang Wen +24 位作者 Gui-ling Wang Xian-peng Jin Lin-you Zhang Hai-dong Wu Wen-shi Wang Cheng-ming Ye Wei Weng Kuan Li Jin-sheng Wu Xian-chun Tang Chong-yuan Zhang Qing-da Feng Sheng Lian Li-sha Hu Gui-lin Zhu Xing-long Xie Bin Wu Dan Wang Xue Niu Zhao-xuan Niu Dong-lin Liu Hui Zhang Wen-hao Xu Shu-qing Yao Li Yang 《China Geology》 CAS CSCD 2024年第3期409-421,共13页
The Hot Dry Rock(HDR)is considered as a clean and renewable energy,poised to significantly contribute to the global energy decarbonization agenda.Many HDR projects worldwide have accumulated valuable experience in eff... The Hot Dry Rock(HDR)is considered as a clean and renewable energy,poised to significantly contribute to the global energy decarbonization agenda.Many HDR projects worldwide have accumulated valuable experience in efficient drilling and completion,reservoir construction,and fracture simulation.In 2019,China Geological Survey(CGS)initiated a demonstration project of HDR exploration and production in the Gonghe Basin,aiming to overcome the setbacks faced by HDR projects.Over the ensuing four years,the Gonghe HDR project achieved the first power generation in 2021,followed by the second power generation test in 2022.After establishing the primary well group in the initial phase,two directional wells and one branch well were drilled.Noteworthy progress was made in successfully constructing the targeted reservoir,realizing inter-well connectivity,power generation and grid connection,implementing of the real-time micro-seismic monitoring.A closed-loop technical validation of the HDR exploration and production was completed.However,many technical challenges remain in the process of HDR industrialization,such as reservoir fracture network characterization,efficient drilling and completion,multiple fracturing treatment,continuous injection and production,as well as mitigation of induced seismicity and numerical simulation technology. 展开更多
关键词 Power generation Hot dry rock(HDR) Enhanced geothermal system(EGS) Genesis mechanism Gonghe Basin Directional drilling Reservoir construction Circulation test Induced seismicity Clean energy exploration engineering
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Conventional Geothermal Systems and Unconventional Geothermal Developments: An Overview
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作者 Maryam Khodayar Sveinbjörn Björnsson 《Open Journal of Geology》 CAS 2024年第2期196-246,共51页
This paper provides an overview of conventional geothermal systems and unconventional geothermal developments as a common reference is needed for discussions between energy professionals. Conventional geothermal syste... This paper provides an overview of conventional geothermal systems and unconventional geothermal developments as a common reference is needed for discussions between energy professionals. Conventional geothermal systems have the heat, permeability and fluid, requiring only drilling down to °C, normal heat flow or decaying radiogenic granite as heat sources, and used in district heating. Medium-temperature (MT) 100°C - 190°C, and high-temperature (HT) 190°C - 374°C resources are mostly at plate boundaries, with volcanic intrusive heat source, used mostly for electricity generation. Single well capacities are °C - 500°C) and a range of depths (1 m to 20 Km), but lack permeability or fluid, thus requiring stimulations for heat extraction by conduction. HVAC is 1 - 2 m deep and shallow geothermal down to 500 m in wells, both capturing °C, with °C are either advanced by geothermal developers at <7 Km depth (Enhanced Geothermal Systems (EGS), drilling below brittle-ductile transition zones and under geothermal fields), or by the Oil & Gas industry (Advanced Geothermal Systems, heat recovery from hydrocarbon wells or reservoirs, Superhot Rock Geothermal, and millimeter-wave drilling down to 20 Km). Their primary aim is electricity generation, relying on closed-loops, but EGS uses fractures for heat exchange with earthquake risks during fracking. Unconventional approaches could be everywhere, with shallow geothermal already functional. The deeper and hotter unconventional alternatives are still experimental, overcoming costs and technological challenges to become fully commercial. Meanwhile, the conventional geothermal resources remain the most proven opportunities for investments and development. 展开更多
关键词 Conventional Geothermal Systems Unconventional Geothermal Developments Shallow and Deep Closed-Loops Enhanced Geothermal Systems Supercritical and Millimeter-Wave Drilling
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Osteotomy Protocol for Implant Insertion of One Day Biotech: One Drill, One Implant
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作者 Jin Hwan Kim Jaehyun Song +3 位作者 Jaegyun Choi Jose Francisco Ballester Ireh Kim Santiago Jose Ballester 《Open Journal of Stomatology》 2024年第5期255-277,共23页
Background: Four factors determine the quality of an implantology kit: 1) Heat generated by the drills;2) Morphology of the osteotomy according to the diameter of the implant;3) Efficiency of collecting autologous bon... Background: Four factors determine the quality of an implantology kit: 1) Heat generated by the drills;2) Morphology of the osteotomy according to the diameter of the implant;3) Efficiency of collecting autologous bone;and 4) Osteotomy execution time. Materials and Methods: This article examines the heat produced by drills during osteotomy, focusing on the effect of the following factors: drilling technique;volume of autologous bone harvested;drilling time;implant primary stability;and the percentage of osseointegrated implants after primary healing. Discussion: The four factors mentioned above are analyzed based on the data obtained for sequential, biological, and One Drill milling techniques. Conclusions: 1) One Drill is the fastest technique for performing the osteotomy;2) All techniques stay within the biological temperature range of living bone, with the lowest increase in temperature achieved using One Drill with irrigation;3) The bone harvested showed no statistically significant differences between biological milling and the One Drill technique, both far superior to the sequential technique;and 4) There is no statistically significant difference in the number of osseointegrated implants among the three techniques analyzed. 展开更多
关键词 Dental Implant Bur Primary Stability Drilling Time OSTEOTOMY Irrigation Bone Collected
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