为了优化套管锻铣工具结构,对活塞及刀体等核心机构的作用力传递关系进行充分分析,采用理论计算及有限元仿真两种计算方法,建立了活塞推力与单翼刀体和套管之间接触力的定量关系公式,并分析了活塞推力对套管局部屈服的影响.结果表明,随着活塞上的压力不断增加,接触反力和施加的活塞推力是线性关系,两者比值约为1:3,并且活塞推力对套管材料局部屈服的影响并不明显,在套管锻铣工具设计中,优先选择合适的节流喷嘴,使产生的活塞载荷能够确保工具在套管上不打滑即可,然后在转矩和钻压作用下,刀体就可切削套管.该研究为套管锻铣工具后续节流喷嘴尺寸的选择、工具施工参数的优选提供了理论依据.

在大尺寸连续循环阀研发的基础上研制了外径为133 mm的连续循环阀,通过数值模拟方法评价了连续循环阀本体、旁通阀应力分布特点,分析了旁通循环时的内部流场分布规律,确保了工具的强度安全.研制的样机通过拉扭试验和密封性能测试,开展现场试验并取得了成功,工具整体设计性能达到了预期目的,为小井眼连续循环钻井技术的应用提供了可靠的工具.

页岩储层通常呈薄层状结构,一般认为其岩石力学参数具有横向各向同性,而其各向异性受围压(CP)、含水率和总有机质含量(TOC)等多种因素的影响.本文对不同围压下的鹰滩(Eagle Ford)页岩进行超声波波速测试实验,研究围压对鹰滩页岩波速及岩石力学各向异性的影响.实验结果表明,鹰滩页岩属于弱各向异性多孔介质,并具有横向各向同性、垂向各向异性的性质.纵波(P波)和横波(S波)波速随围压的增大而增大,特别是在低围压范围内增幅显著,同时围压增大会降低纵波和横波的各向异性,纵波各向异性比横波各向异性对围压更敏感.对鹰滩页岩的各向异性分析为页岩储层压裂过程中裂缝的起裂和延伸规律研究提供了必要的力学参数.

钻井过程中,当完成一单根或立柱钻进后,需要停止钻井液循环、卸开方钻杆或顶驱与钻杆的螺纹连接,在这两者之间接入新的钻杆,然后再重新启动泥浆泵恢复钻井液的循环,周而复始,从而实现井眼向地层的延伸.钻井液作为钻井工程的血液,其不但起到冷却钻具、携带岩屑的作用,还具有平衡地层压力的功能.除了在特殊钻井技术情况以外,钻井液在井底产生的液柱压力要大于地层孔隙压力、小于地层岩石的破裂压力,而在深部地层钻井和海上钻井时孔隙压力和破裂压力差值特别小,即窄密度窗口地层.停开泥浆泵循环会造成井底压力的波动,并且停止钻井液循环,井底压力为钻井液静液柱压力,将比钻井液循环时在井底造成的压力少了一个循环压耗,表现为钻井液液柱压力小于孔隙压力或者大于地层破裂压力,从而导致井控事故或井下垮塌、井漏等事故复杂的发生,2003年造成243人死亡的四川开县12?23事故即是钻井液液柱压力小于孔隙压力的严重井控事故和环境灾难.采用控压钻井和连续循环钻井技术是解决该问题的新技术.

钻井过程中,钻柱承受着拉扭等多种交变载荷的作用,其损伤机理一直是力学界深入研究的课题。笔者首先根据细观力学分析的基本原理,采用Abaqus软件的脚本语言Python建立细观尺度下晶粒分布模型,然后采用断裂力学算法——扩展有限元法对含有微裂纹的细观尺度下晶粒模型进行计算,分析裂纹的动态扩展过程以及相应的应力应变分布特征,最后根据细观力学中"均匀化"方法对不同时刻的应力应变进行处理,得到微裂纹扩展对钻杆材料宏观性能的影响。在宏观尺度下处于弹性阶段的钻杆材料,在细观尺度下仍会出现塑性区,且在微裂纹不扩展的情况下,弹性模量是恒定的。文章提出的思路为深入探索钻柱材料断裂机理提供了新的方法。

We propose a method for calculating the cuttings (solids) concentration in the annular space and the equivalent circulating density (ECD) in deepwater drilling, both in the pilot hole drilling step and in the reaming step. We have found that drilling a pilot hole followed by reaming has certain advantages over drilling with no pilot hole. When using technology involving preliminary drilling of a pilot hole, the solids concentration in the annular space and the equivalent circulating density are reduced.

气体钻井有提高机械钻速、避免井漏等诸多优点,但在地层出水时接单根/立柱导致井内积水严重,浸泡井壁和注气压力增加、井底压力波动,而引起井下事故复杂的发生.针对苏里格地区水层多、水量大特点,开展了气体连续循环钻井作业,得到了接立柱过程中立管压力变化曲线,即马-魏曲线,该曲线证实了气体连续循环钻井技术的有效性和实用性,实现了在不停注气情况下接立柱过程中维持恒定的钻井循环排量和当量循环密度,同时持续携带地层水、防止因地层水聚集引起过高的立管压力,确保气体钻井安全.

In order to reduce the repairing and testing time and to improve the working perform-ance and the technical service quality of the intelligent drilling tool,an oil filling and testing equip-ment for the steering executive unit was developed.The testing bench and the oil way were de-signed on the basis of analyzing the working principle of the unit.According to different series of intelligent drilling tools,removable pedestals equipped with oil inlet and oil outlet were designed for the components’fixation.The oil inlet and oil outlet of every pedestal are connected by the hydraulic pipeline.By this way the test bench can completely simulate the functions of the tool’s hydraulic system.The hydraulic circuit layout includes oil-filling-way and scavenge-oil-way which is connected by oil-filling-nozzle and scavenge-oil-nozzle independently.The hydraulic circuit is used for the oil filling and testing of the hydraulic system.The result shows that,the equipment meets the design requirement.Before assembling the performance of all hydraulic parts can be tested and the oil filling and venting procedure for the tool can be performed after the parts as-sembly.Thus the stable hydraulic thrust can be generated and the working stability of the tool can be improved.

连续循环钻井技术是能在接单根或立柱以及起下钻过程中保证钻井循环介质的连续不断的注入、维持恒定的钻井循环排量和当量循环密度、避免井下压力波动引起复杂事故发生的一项新技术，其中连续循环阀钻井系统是最为容易实现的方式，该系统的核心是连续循环阀。介绍了一种气液通用的连续循环阀，并采用 ABAQUS 有限元软件对连续循环阀本体和旁通阀进行强度校核，确保工具的安全性，最后通过室内气液密封测试证实其密封可靠性。该连续循环阀在苏76-43-35井上成功进行连续循环钻井测试，实现了接立柱过程中钻井液连续循环的目的，为降低压力敏感井、复杂结构井的施工难度提供有力技术支撑。

研究元坝地区海相碳酸盐岩气藏打孔衬管完井渗流规律,在充分考虑真实天然气的偏差因子、密度以及黏度随压力变化情况的基础上建立渗流数学模型;同时利用COMSOL Multiphysics软件对该模型进行求解计算,获得打孔衬管完井方式下近井壁的渗流场分布.研究表明:衬管完井渗流场中从供给边界到井底之间压力表现为明显的“压降漏斗”趋势,与常规解析解趋势相一致;当气体在远离井筒位置时渗流速度很小并且流速接近稳定,在井筒附近区域渗流速度分布呈波浪式,其中两端的渗流速度最大,为速度敏感性分析的重点.

Based on a brief introduction of the development of the continuous circulation valve both at home and abroad,the article also describes the working principle and characteristics of different structure continuous circulation valve. At last,the article discusses the development trend of the continuous circulating valve,and points out the direction for the research of continuous circulation valve.

针对元坝地区含裂缝储层,在充分考虑含裂缝储层裂缝孔隙度、渗透率以及真实天然气物性的基础上,分别建立含45°倾斜裂缝、水平裂缝和垂直裂缝有限元模型,利用Comsol Multiphysics软件对含裂缝储层模型渗流场进行计算,得到含裂缝储层中近井壁的渗流场分布规律.从中进一步研究不同裂缝对基岩渗流速度的影响程度.研究得出;含裂缝储层渗流场中,在裂缝穿过的地层中,等压面上的压力弱有变化,表现为光滑等压面有折断趋势,相同的压力在裂缝更靠近井底.裂缝对基岩内渗流场分布影响并不大,但裂缝内的渗流速度相对于基岩内渗流速度有数量级上的变化,会显著的增加单井产量.因此在低渗地层尽量利用贯穿裂缝或人工造缝提高地层导流能力.

为了得出元坝地区海相碳酸盐岩气藏割缝衬管完井渗流规律，在充分考虑真实天然气的偏差因子、密度以及黏度随压力变化的基础上，建立了渗流数学模型，并利用Comsol M ultiphysics软件对该模型进行求解计算，得到衬管完井方式下近井壁的渗流场分布。通过从 X平面提取若干条割线，进一步分析各割线处压力的分布特点；最后对裸眼完井渗流场进行对比，计算出衬管完井的产能比。研究得出：在割缝衬管完井渗流场中从供给边界到井底之间的压力表现为明显的“压降漏斗”趋势，与常规解析解趋势相一致。当气体在远离井筒位置时渗流速度很小并且流速接近稳定，在井筒附近区域渗流速度分布呈波浪式，其中两端的渗流速度最大，为速度敏感性分析的重点。定量分析了割缝衬管完井的产能比，结果表明割缝衬管完井的产能比裸眼完井的产能下降了2／3。

The aim of this study is to optimize a method used to design the trajectory of horizontal wells. Many of the well-known can be used for various types of well (directional, horizontal, extended-reach, sidetrack horizontal, etc.) and for various curvature radii (long, medium, short, and ultrashort), but while the resulting trajectories meet standard field operation requirements they are still suboptimal. The research done here not only optimizes the angle of inclination of the linear (tangent) section of the well but also accounts for the forces created by rock debris and the equivalent circulating density (ECD) of the drilling fluid.

为优选元坝地区海相碳酸盐岩气藏射孔完井参数,在充分考虑真实天然气的偏差因子、密度及黏度随压力变化的基础上,建立了渗流数学模型,并利用COMSOL Multiphysics软件进行求解计算,得到射孔完井方式下近井壁的渗流场分布.文中从X平面提取若干条割线,进一步分析各割线处压力的分布特点;然后改变射孔完井的各个参数,建立有限元模型,计算出不同参数下射孔完井的产能比.计算结果表明,射孔完井渗流场中,从供给边界到井底压力为明显的“压降漏斗”趋势,与常规解析解趋势一致.在影响射孔完井产能的参数中,主要是孔深、孔密、孔径和相位角,其中孔深对产能的影响最大,其次是相位角.

The high-speed gas flow in tubing causes erosion damage to the string for high pressure and high production gas wells,and the erosion threats the security of gas production and operation seriously.The tubing string with packers tends to be buckled,making the erosion more damaging,which is prone to cause downhole string failure or even well field accidents.Therefore,considering the flow channel features in the tubing string of sine buckling and helical buckling,based on the theory of the natural gas flowing dynamics,the CFD model and sand erosion model were established for a high pressure and high production gas well in Kela 2 gas field.Numerical simulation was conducted on the flow performance of natural gas in sine and helical buckled tubing string,and the erosion velocity and shear stress of sand flowing in the tubing was studied.The force and erosion law of natural gas to buckled tubing were obtained.It provided a reference for real-time prediction of erosion damage in high pressure and high production gas wells,and a theoretical basis for the proposal of erosion damage prevention measures.

Traditional fuzzy comprehensive evaluation method has some defects in fracture acidizing well and layer selection,therefore is improved by using optimal membership degree matrix,fuzzy analytic hierarchy process and non-linear fuzzy matrix composite operator.The modified model can take account of influencing factors,weigh technical and economical indices,and solve the optimal membership degree of fracturing well and layer.The result of the modified model coincides with the actual practice,can provide theoretical basis for optimization of fracturing scheme and fracture acidizing well and layer.

This article makes a new simulation of bottom hole assembly(BHA) through the finite element analysis software and then gets drilling tools inherent frequency,vibration mode and vibration rule under the different external conditions.At the same time,this paper puts forward a view that in the drilling process,the simple and practical method to avoid resonance is to change drilling pressure.

The couple calculation of seepage field and stress field is completed by using the software of COMSOL Multiphysics based on the basic theory of fluid-solid coupling and the consideration of the variation in permeability,thus obtaining the distribution of pressure and permeability of the couple seepage field in the direction normal to main hole,which is used to analyze seepage law.The results of the study show that the variation in permeability in the vicinity of wellbore is obvious,the integral seepage field of coupled field is greater than individual seepage field and the calculated production rate in the coupled field is less than that in the individual field.Therefore,it is the seepage field of fluid-solid couple seepage field that can truly reflect the permeable flow in formation.The effects of 3 types of branch wells on formation parameters are compared through the process of weighted average volume for all the formation parameters,thus providing technical bases for reservoir development.