Research into magnetic guidance technology for directional drilling in SAGD horizontal wells

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.

Research on Horizontal Vibration of Heavy-Weight Drill Pipes in Directional Drilling

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.

Application and development of numerical simulation for under- ground horizontal directional drilling

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.

Stress Analysis of Buried Pipeline Installed by Horizontal Directional Drilling Using ANSYS Finite Element Software

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%.

Surface settlement induced by horizontal directional drilling

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.

基于颗粒流计算的砾石层HDD导向孔水平段孔壁变形研究

水平定向钻进技术在城市管线铺设中应用越来越广,砾石作为松散颗粒的集合体,在进行导向孔钻进时,往往由于颗粒结构扰动而易发生变形甚至塌孔,但颗粒在钻进过程中的力学行为规律仍不明晰。本文利用颗粒流程序建立三维砾石模型,并分段进行有和无泥浆护壁导向孔水平段钻进模拟。通过在导向孔周围布设测量球,对导向孔周围颗粒变形特征进行研究。结果表明:孔壁失稳表现为上部颗粒相互嵌固形成“压力拱”,压力拱下部松散颗粒率先掉落,伴随着压力向两侧和底部传递,下部和侧向颗粒协调变形直至收敛。压力拱在后续钻孔扰动下,由于侧向约束的消除,压力拱向顶部扩展,产生更多的松散颗粒进入钻孔范围,最终导致塌孔。泥浆可以较好的约束松散颗粒的顶部掉落,维护压力拱的侧向约束。实际工程中应量化泥浆指标,选择合理的泥浆而避免塌孔事故发生。

Estimation of the horizontal in-situ stress magnitude and azimuth using previous drilling data

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.

Laboratory study of fluid properties owing to cutting intrusions during horizontal directional drilling

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.

放顶煤工作面以孔代巷合理布孔参数

为了解决刘家梁矿2号煤层低含量赋存高强度开采引发工作上隅角瓦斯问题,缓解矿井因岩巷掘进造成采掘接替紧张的局面,提出了采用大直径高位走向长钻孔代替工作面低位岩石抽采巷的瓦斯治理技术,结合矿井2号煤层顶板煤岩物理力学参数,通过理论分析、UDEC、FLUENT数值模拟的方法,分别从工作面裂隙带发育、工作面采空区流场分布等不同的专业角度,分析、研究了瓦斯流通通道及赋存规律,为定向高位钻孔合理布孔层位选择提供理论支撑;结合1号钻场瓦斯抽采效果,修正工作面煤岩赋存资料,优化2号钻场抽采设计,调整钻孔布置参数,以工作面瓦斯抽采纯量、上隅角瓦斯浓度为指标,对不同条件下瓦斯治理效果进行对比,实践证明:走向高位长钻孔能够取代低位岩石抽采巷,用于低含量赋存、高强度开采的放顶煤工作上隅角瓦斯治理,治理效果显著,上隅角瓦斯浓度维持在0.6%以下。

三维可视化HDD钻导向孔钻柱力学分析软件的研制与应用——以3300m长江天然气管道穿越工程为例

钻导向孔的成功与否是决定3 300m长江天然气管道穿越工程成败的关键,需要对钻导向孔的钻柱进行力学分析,提前判断钻柱的受力情况,并判断钻具组合是否满足施工要求。为此,综合利用传统的软钻柱模型和较新的ABIS模型,研发了HDD钻导向孔钻柱力学分析软件,可进行钻导向孔时钻柱的受力分析和三维图像显示。将该软件与国外常用的Ridgewood Software(RS)软件进行对比,从井口推力及井口扭矩来看,两者的计算结果很接近;同时还将该软件在某管道穿越工程中进行了模拟应用,将软件计算结果与实测数据进行了比较。结果表明:HDD钻导向孔钻柱力学分析软件能够很好地预测钻导向孔时钻柱的力学状态,并能用三维图像直观地显示导向孔内钻杆的变形与应力分布情况。该软件的成功研制与应用,为长江3 300m天然气管道穿越工程钻导向孔的钻具组合提供了技术支持,其国产化对管道穿越工程钻导向孔的设计和大规模的工程应用奠定了基础。

GY-2000L型双动力头钻机在新疆额敏抽水蓄能项目水平定向钻孔中的应用

在新疆额敏抽水蓄能电站勘察任务中,使用GY-2000L新型双动力头岩心钻机,完成735 m空间曲线导向绳索取心钻进,倾角从14°定向至水平0°,钻孔轨迹方位角从236°定向至262°,精准实现靶区取心勘探目的。该钻孔“空间曲线精准造斜到靶区+水平绳索连续取心”工法,硬岩导向钻进435 m,复杂地层绳索取心钻进300 m,靶区岩心采取率大于98%,在水利行业工程勘察创新了水平定向绳索取心工艺技术,为该区同类钻孔施工提供宝贵经验和借鉴依据。

H24-16柔性多分支侧钻水平井钻井实践与认识

江苏油田H24-16井存在砂体能量弱、储层薄、渗透率低及注水不见效等问题。柔性多分支侧钻水平井技术将开窗、造斜、钻进所有进尺全部集中在目标储层,可以实现分支长度与储层接触面积最大化。为挖掘该井薄差层剩余油,研制了柔性钻具、叠加式斜向器及专用打捞矛,设计了分支井眼轨道,辅以井眼轨迹控制,完成了H24-16井的柔性多分支侧钻水平井钻进。首次成功实现了江苏油田在同一油层钻出2个分支水平井眼,为高效侧钻挖潜剩余油积累了宝贵经验,具有较大的推广应用价值。

上软下硬地层近距离下穿既有盾构区间注浆加固关键技术

依托广州某新建大直径盾构隧道下穿既有盾构区间项目,研究了在富水花岗岩地层中复杂周边环境条件下的地层加固技术以及下穿过程中的关键施工措施。结合施工条件,对新建盾构区间采取水平定向钻注浆、先行洞预留注浆孔注浆、盾构机超前注浆结合的主动注浆方式;对既有线进行预注浆加固的被动注浆方式。施工过程中,采用控制掘进参数、渣土改良、同步克泥效等控制手段,保证了盾构下穿过程的顺利进行。

水平定向钻穿越水敏性地层冒浆预测及防控

非开挖水平定向钻穿越施工中,孔内压力过高会造成地表隆起冒浆事故,严重污染周围环境,造成重大经济损失。以福州市塘坂引水工程供水管道水平定向钻穿越项目为例,考虑工程水敏性软化造浆地层,基于Mohr-Coulomb准则构建了针对水敏弱膨胀地层的孔内最大允许泥浆压力计算模型,并通过现场位移监测数据验证了模型的正确性;随后通过现场应用校验了非开挖水平定向钻穿越水敏弱膨胀地层的冒浆防控技术可靠性。研究结果表明:所推导的计算模型比现有其他孔内允许泥浆压力预测模型更加适用于水敏性软化造浆地层;水平定向钻穿越冒浆防控技术应以孔内泥浆压力控制为主,结合泥浆技术、工艺优化防止憋压,最后辅以局部薄弱点加强、定向控制冒浆等手段进一步加强冒浆预防措施,保障施工安全。

典型煤矿区小煤窑老空水探查治理关键技术及其应用

以峰峰矿区辛安矿为例,经探查在+32 m、-100 m水平矿井涌水量中,周边小煤窑老空水约占总涌水量的70%。现已探明采空区内有3处重要涌水点均在大青灰岩含水层,最大涌水量可达6 m^(3)/min。由于涌水点位于封闭采空区,井下不具备定向钻探施工的条件。因此,拟采用地面多分支水平井定向钻探技术对大青灰岩含水层进行探查,通过综合运用超浅垂深定向施工、立体通道精细探查、定向水平孔投料、过水通道动水快速封堵等关键技术,不仅可以高效的识别出采空区涌水点,而且经现场抽水验证,地面多分支水平井注浆技术能够对井下突水点精准有效封堵。

水平定向钻技术在岩土工程勘察中的应用

针对岩土工程勘察问题,提出一种新的水平定向钻技术,其具有勘察精度高、适用范围广、环境友好等特点,解决了传统垂直定向钻中设备移动困难、费时费力的问题,实现了远距离的精准钻芯检测。工程实践应用表明,水平定向钻技术通过取芯测试、地应力测试、综合测井、CCTV检测等流程,不仅可准确记录钻进速度、深度等指标,还能借助地面接收器对孔内影像实时观测,自动存储全部影像资料。

近水平煤层长距离采空区定向疏水钻孔选择方法研究

【目的】为解决近水平煤层长距离采空区定向疏水钻孔选择的难题,需要一套量化评价的方法,为矿井探放水工程施工提供依据。【方法】本研究通过构建近水平煤层长距离采空区定向疏水钻孔水量计算模型,以伯努利方程为基础,综合分析开孔位置、孔径、孔深等参数,推导单孔及分支孔涌水量计算公式。【结果】以母杜柴登煤矿实际施工的采空区定向疏水钻孔为例,分析对比计算公式的准确性,同时对近水平煤层条件下单孔与分支孔水量、经济效益进行对比分析。【结论】得出了近水平煤层长距离采空区定向疏水钻孔布置的影响因素和选择方法。该方法准确性较高、计算简便,为类似矿井采空区水害治理提供了一定的借鉴和参考。

管线穿越高等级公路沉降观测方法浅析

以某市循环产业园燃气管线下穿京台高速为背景,研究了水平定向钻施工方法对公路路基沉降变形的影响及相应的监测方法。借鉴给排水顶管技术对地表的变形预测和计算方法,通过Peck公式计算路基最大沉降量及影响的区域,根据《建筑变形测量规范》(JGJ8-2016)确定变形监测精度等级,结合工程实际情况设计沉降观测点的布置点位,根据施工特点确定监测频率、观测方式,总结了水平定向钻方法施工过程中沉降观测应注意的事项及与一般建筑物沉降观测的不同之处,最后通过项目的实测数据检验沉降观测方案的合理性、可行性及待改进之处,并对Peck公式的适用性进行了有效验证。

关于正交试验在碱性水环境下定向钻泥浆的配比研究

如何配制出良好的泥浆使其能够在管道中形成稳定的泥膜,以保持管壁稳定性是目前行业内研究的重点。研究主要以黄河穿管项目为背景,以膨润土、羧甲基纤维素、碳酸钠等为材料,通过研究不同配比下泥浆的性能来研究影响泥浆的因素。本次试验结果表明:根据本项目背景工程,通过设计正交试验得出膨润土∶CMC∶碳酸钠∶水=80∶4∶5∶900为良好的泥浆配比。

供热管道穿越岩层水平定向钻施工技术分析

为分析水平定向钻施工技术在供热管道穿越岩层情况下的应用效果,以兰州城区供热管道改造工程为例,展开相关研究。通过分析该施工区域的地质情况,选择施工设备并确定施工步骤以及相关的施工参数,并计算施工时所需的最小的泥浆压力和最大允许的泥浆压力,以此完成供热管道穿越岩层水平定向钻施工,并获取该技术的施工轨迹结果,为相关工程施工提供可靠依据。