SAGD horizontal wells are used to enhance oil recovery from heavy oil reservoirs.This technology requires precise separation between the production well and the injection well to ensure the efficient drainage of the r...SAGD horizontal wells are used to enhance oil recovery from heavy oil reservoirs.This technology requires precise separation between the production well and the injection well to ensure the efficient drainage of the reservoir.By studying the attitude of the downhole probe tube and the production well trajectory,an algorithm is proposed for eliminating ferromagnetic interference while drilling injection wells.A high accuracy filter circuit has been designed to correct the detected magnetic signals,which are ultra-weak,frequency-instable,and narrow-band.The directional drilling magnetic guidance system（DD-MGS） has been developed by integrating these advanced techniques.It contains a sub-system for the ranging calculation software,a magnetic source,a downhole probe tube and a sub-system for collecting ＆ processing the detected signals.The DD-MGS has succeeded in oilfield applications.It can guide the directional drilling trajectory not only in the horizontal section but also in the build section of horizontal injection wells.This new technology has broad potential applications.展开更多
In coalmines of China, horizontal directional drilling （HDD） is an increasingly popular method for underground in-seam gas drainage. Numerical simulation, especially finite element analysis, is often used as an effe...In coalmines of China, horizontal directional drilling （HDD） is an increasingly popular method for underground in-seam gas drainage. Numerical simulation, especially finite element analysis, is often used as an effective method to improve HDD operation. These improvements focus on rock-breaking efficiency, directional precision, stability of the borehole wall, and reliability of the drill equipment. On the basis of underground drilling characteristics, typical numerical simulation exam- ples in drilling techniques and equipment are summarized and analyzed. In the end, the future development trends of numerical simulation in underground in-seam drilling are proposed.展开更多
The mode of load and deformation of directional drilling string and the expression of trigonometric series of deflection equation are established by means of elastic deformation energy and of the vertical and horizont...The mode of load and deformation of directional drilling string and the expression of trigonometric series of deflection equation are established by means of elastic deformation energy and of the vertical and horizontal bending. A calculation formula for natural frequency of horizontal resonance and rotational speed is derived based on the calculation method by Ritz, with which analysis is made for the cause and affecting factors of the excessive abrasion of heavy-weight drill pipe in high-angle holes so as to provide reference and basis for rational selection of drilling parameters and drilling tools in the future high-angle directional drilling.展开更多
In designing a horizontal directional drilling (HDD) pipeline project, designers face the challenge of determining the regions of maximum and minimum stresses on pipelines, ensuring the stability of the bore-hole from...In designing a horizontal directional drilling (HDD) pipeline project, designers face the challenge of determining the regions of maximum and minimum stresses on pipelines, ensuring the stability of the bore-hole from collapse and minimizing the stresses induced on the pipeline due to the bore-profile. This study analyses the stress induced on an HDD pipeline system using the ANSYS Version 18, mechanical APDL finite element (FE) software. The pipeline used as the case study was a gas transmission pipeline installed in south-west Nigeria. A macro-file for ANSYS Version 18, mechanical APDL used to model the pipeline was developed. The results showed that the maximum and minimum stresses induced on the HDD pipeline were at the top and bottom of the pipe, respectively;while the stresses on the sides were uniform (≈888 kg/cm2) all through the pipeline, irrespective of element number. The maximum stress occurred at the curvature point with the highest entry angle (10°), resulting in a maximum deflection at this point. The model stress validation performed by comparing results with theoretical solutions, both with respect to radius of curvature and internal pressure, showed percentage difference (errors) less than 10%. The cross sectional area validation showed a percentage difference of 0.059%.展开更多
Horizontal directional drilling(HDD)is a widely used trenchless method for underground utility connections.The associated ground settlement triggered by HDD depends on the size,types,and surface texture of pipe,diamet...Horizontal directional drilling(HDD)is a widely used trenchless method for underground utility connections.The associated ground settlement triggered by HDD depends on the size,types,and surface texture of pipe,diameter of borehole,and soil conditions.The pre-sent study investigates the surface settlement due to the construction of a 1067 mm diameter HDD,which will replace an existing sewer siphon under the SR-60 highway in Chino,California using empirical,and numerical methods.Based on the results obtained from the subsurface investigation,an empirical analysis was conducted first.followed by numerical modeling of the HDD using PLAXIS 2D soft-ware.A careful comparison between two different methods indicated closer values of surface settlement between the empirical method(7.3 mm)and the numerical modeling(4.6 mm).In addition,the shape of surface settlement and horizontal settlement curves for the empirical and numerical methods was found to be similar.The minor discrepancy between the two methods resulted as the numerical model can host several soil layers whereas the empirical equation can use only one type of soil.Finally,a parametric study was conducted to evaluate the effect of borehole cover depth,size,and soil parameters on surface settlement.It was observed that soil strength param-eters yielded a greater effect on surface movement,whereas modulus of elasticity has a relatively smaller influence with zero contribution from Poisson’s ratio.展开更多
During horizontal directional drilling installations,a primary function of drilling fluids is to yield drill cuttings and lubricate the product pipe.This paper presents the results of a research study of drilling flui...During horizontal directional drilling installations,a primary function of drilling fluids is to yield drill cuttings and lubricate the product pipe.This paper presents the results of a research study of drilling fluid parameters,and the filter cake properties associated with drill cutting intrusions.Different sand meshes and field cutting sizes were added to the drilling fluids.Based on the laboratory experiments of eighteen samples including testing drilling fluid rheology and filter cake properties,the influence of drill cuttings on low solid-phase drilling fluid systems were obtained.The results reveal that drilling fluid plastic viscosity values increase with sand content and particle size.The 100-mesh sand exhibits a larger plastic viscosity compared to the 200-mesh sand.This suggests that the coarser the sand,the greater is the plastic viscosity.By contrast,drilling fluids with 200-mesh sand exhibit greater shear forces than the 100-mesh sand.When the sand content is4%,the shear dilution ability of the drilling fluid begins to weaken.The thinnest filter cake is formed after 6 h with a 100-mesh cutting size and 4%sand content.However,when the cutting size changed to 150-mesh and 2%content,the largest filter cake toughness and strength after rolling for 12 h were obtained.Simultaneously,the combination of 200-mesh and 150-mesh with 2%–4%content rolling for 12–24 h indicate different results.For the filter cake thickness,cutting content is the primary influencing factor followed by particle size and gradation.The factor with the least influence is rolling time.We found that rolling time and gradation were the most significant factors affecting the toughness of the filter cake,followed by cutting content.Conversely,particle size exhibits the least influence on filter cake toughness.These results are important to better understand the solid-phase control of drilling fluids in the field.展开更多
Oil exploration and production,well stability,sand production,geothermal drilling,waste-water or CO_(2) sequestration,geohazards assessment,and EOR processes such as hydraulic fracturing,require adequate information a...Oil exploration and production,well stability,sand production,geothermal drilling,waste-water or CO_(2) sequestration,geohazards assessment,and EOR processes such as hydraulic fracturing,require adequate information about in-situ stresses.There are several methods for analyzing the magnitude and direction of in-situ stresses.The evaluation of tensile fractures and shear fractures in vertical oil and gas wellbores using image logs is one of these methods.Furthermore,when image logs are run in boreholes,they can be extremely costly and possibly stop the drilling.The data for this study were gathered from seven directional wells drilled into a strike-slip fault reservoir in southern Iran.Vertical stress,minimum horizontal stress,pore pressure,Poisson's ratio of formations,and 233 mud loss reporting points make up the entire data.This is the first time maximum horizontal stress direction has been calculated without referring to image log data.In addition,the points of lost circulation were categorized into natural and induced fracture.The results revealed that,the maximum horizontal stress direction of the reservoir was calculated at 65northeast-southwest.The error rate is roughly 10when comparing the results of this investigation to those obtained from the image log.The maximum horizontal stress direction is calculated precisely.In terms of tensile fracture pressure,the in-situ stress ratio identifies the safest as well as the most critical inclination and azimuth for each well.展开更多
基金the financial support from the Natural Science Foundation of China (NSFC, 51221003, U1262201)supported by other projects (Grant numbers: 2011ZX05009, 2013AA064803)
文摘SAGD horizontal wells are used to enhance oil recovery from heavy oil reservoirs.This technology requires precise separation between the production well and the injection well to ensure the efficient drainage of the reservoir.By studying the attitude of the downhole probe tube and the production well trajectory,an algorithm is proposed for eliminating ferromagnetic interference while drilling injection wells.A high accuracy filter circuit has been designed to correct the detected magnetic signals,which are ultra-weak,frequency-instable,and narrow-band.The directional drilling magnetic guidance system（DD-MGS） has been developed by integrating these advanced techniques.It contains a sub-system for the ranging calculation software,a magnetic source,a downhole probe tube and a sub-system for collecting ＆ processing the detected signals.The DD-MGS has succeeded in oilfield applications.It can guide the directional drilling trajectory not only in the horizontal section but also in the build section of horizontal injection wells.This new technology has broad potential applications.
基金Supported by the National Natural Science Foundation of China （50805010） the Natural Science Foundation of Shaanxi Province （2011JM70 17）
文摘In coalmines of China, horizontal directional drilling （HDD） is an increasingly popular method for underground in-seam gas drainage. Numerical simulation, especially finite element analysis, is often used as an effective method to improve HDD operation. These improvements focus on rock-breaking efficiency, directional precision, stability of the borehole wall, and reliability of the drill equipment. On the basis of underground drilling characteristics, typical numerical simulation exam- ples in drilling techniques and equipment are summarized and analyzed. In the end, the future development trends of numerical simulation in underground in-seam drilling are proposed.
文摘The mode of load and deformation of directional drilling string and the expression of trigonometric series of deflection equation are established by means of elastic deformation energy and of the vertical and horizontal bending. A calculation formula for natural frequency of horizontal resonance and rotational speed is derived based on the calculation method by Ritz, with which analysis is made for the cause and affecting factors of the excessive abrasion of heavy-weight drill pipe in high-angle holes so as to provide reference and basis for rational selection of drilling parameters and drilling tools in the future high-angle directional drilling.
文摘In designing a horizontal directional drilling (HDD) pipeline project, designers face the challenge of determining the regions of maximum and minimum stresses on pipelines, ensuring the stability of the bore-hole from collapse and minimizing the stresses induced on the pipeline due to the bore-profile. This study analyses the stress induced on an HDD pipeline system using the ANSYS Version 18, mechanical APDL finite element (FE) software. The pipeline used as the case study was a gas transmission pipeline installed in south-west Nigeria. A macro-file for ANSYS Version 18, mechanical APDL used to model the pipeline was developed. The results showed that the maximum and minimum stresses induced on the HDD pipeline were at the top and bottom of the pipe, respectively;while the stresses on the sides were uniform (≈888 kg/cm2) all through the pipeline, irrespective of element number. The maximum stress occurred at the curvature point with the highest entry angle (10°), resulting in a maximum deflection at this point. The model stress validation performed by comparing results with theoretical solutions, both with respect to radius of curvature and internal pressure, showed percentage difference (errors) less than 10%. The cross sectional area validation showed a percentage difference of 0.059%.
文摘Horizontal directional drilling(HDD)is a widely used trenchless method for underground utility connections.The associated ground settlement triggered by HDD depends on the size,types,and surface texture of pipe,diameter of borehole,and soil conditions.The pre-sent study investigates the surface settlement due to the construction of a 1067 mm diameter HDD,which will replace an existing sewer siphon under the SR-60 highway in Chino,California using empirical,and numerical methods.Based on the results obtained from the subsurface investigation,an empirical analysis was conducted first.followed by numerical modeling of the HDD using PLAXIS 2D soft-ware.A careful comparison between two different methods indicated closer values of surface settlement between the empirical method(7.3 mm)and the numerical modeling(4.6 mm).In addition,the shape of surface settlement and horizontal settlement curves for the empirical and numerical methods was found to be similar.The minor discrepancy between the two methods resulted as the numerical model can host several soil layers whereas the empirical equation can use only one type of soil.Finally,a parametric study was conducted to evaluate the effect of borehole cover depth,size,and soil parameters on surface settlement.It was observed that soil strength param-eters yielded a greater effect on surface movement,whereas modulus of elasticity has a relatively smaller influence with zero contribution from Poisson’s ratio.
基金This study was supported by the National Natural Science Foundation of China(No.41602372)open fund of the State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation(Southwest Petroleum University,No.PLN201609&No.PLN201607)+1 种基金fund of Ministry of Land and Resources Key Laboratory of Drilling Technology in Complex Conditions(No.DET201612)the Fundamental Research Funds for the Central Universities of Central South University(No.2018zzts690).
文摘During horizontal directional drilling installations,a primary function of drilling fluids is to yield drill cuttings and lubricate the product pipe.This paper presents the results of a research study of drilling fluid parameters,and the filter cake properties associated with drill cutting intrusions.Different sand meshes and field cutting sizes were added to the drilling fluids.Based on the laboratory experiments of eighteen samples including testing drilling fluid rheology and filter cake properties,the influence of drill cuttings on low solid-phase drilling fluid systems were obtained.The results reveal that drilling fluid plastic viscosity values increase with sand content and particle size.The 100-mesh sand exhibits a larger plastic viscosity compared to the 200-mesh sand.This suggests that the coarser the sand,the greater is the plastic viscosity.By contrast,drilling fluids with 200-mesh sand exhibit greater shear forces than the 100-mesh sand.When the sand content is4%,the shear dilution ability of the drilling fluid begins to weaken.The thinnest filter cake is formed after 6 h with a 100-mesh cutting size and 4%sand content.However,when the cutting size changed to 150-mesh and 2%content,the largest filter cake toughness and strength after rolling for 12 h were obtained.Simultaneously,the combination of 200-mesh and 150-mesh with 2%–4%content rolling for 12–24 h indicate different results.For the filter cake thickness,cutting content is the primary influencing factor followed by particle size and gradation.The factor with the least influence is rolling time.We found that rolling time and gradation were the most significant factors affecting the toughness of the filter cake,followed by cutting content.Conversely,particle size exhibits the least influence on filter cake toughness.These results are important to better understand the solid-phase control of drilling fluids in the field.
文摘Oil exploration and production,well stability,sand production,geothermal drilling,waste-water or CO_(2) sequestration,geohazards assessment,and EOR processes such as hydraulic fracturing,require adequate information about in-situ stresses.There are several methods for analyzing the magnitude and direction of in-situ stresses.The evaluation of tensile fractures and shear fractures in vertical oil and gas wellbores using image logs is one of these methods.Furthermore,when image logs are run in boreholes,they can be extremely costly and possibly stop the drilling.The data for this study were gathered from seven directional wells drilled into a strike-slip fault reservoir in southern Iran.Vertical stress,minimum horizontal stress,pore pressure,Poisson's ratio of formations,and 233 mud loss reporting points make up the entire data.This is the first time maximum horizontal stress direction has been calculated without referring to image log data.In addition,the points of lost circulation were categorized into natural and induced fracture.The results revealed that,the maximum horizontal stress direction of the reservoir was calculated at 65northeast-southwest.The error rate is roughly 10when comparing the results of this investigation to those obtained from the image log.The maximum horizontal stress direction is calculated precisely.In terms of tensile fracture pressure,the in-situ stress ratio identifies the safest as well as the most critical inclination and azimuth for each well.
