Managed Pressure Drilling Technology,As the Lost Piece of the Drilling Puzzle,Results in More Economical Benefits

The economics of drilling wells is important as we drill deeper wells whether offshore or onshore. Drilling-related problems,including stuck pipe,lost circulation,and excessive mud cost,show the need for better drilling technology.If we can solve these problems,the economics of drilling the wells will improve,thus enabling the industry to drill wells that were previously uneconomical.Managed pressure drilling techniques,at one time,having

A dynamic managed pressure well-control method for rapid treatment of gas kick in deepwater managed pressure drilling

During deepwater managed pressure drilling(MPD),the gas kick may occur in abnormally high-pressure formations.If the traditional well control method is adopted,the treatment time is long and the advantage of early gas kick detection of MPD is lost.The dynamic managed pressure well-control(MPWC)method can be used to rapidly treat gas kick in deepwater MPD.In this paper,considering the effect of large-variable-diameter annulus and complex wellbore temperature in deepwater drilling,a simplified model of non-isothermal gas-liquid two-phase flow was established for dynamic deepwater MPWC simulation.Using this model,the response characteristics of outlet flow and wellhead backpressure were investigated.The results indicated that the gas fraction,outlet liquid flow rate,pit gain and wellhead backpressure presented complex alternating characteristics when gas moved upwards in the wellbore due to the large-variable-diameter annulus.The outlet liquid flow rate would be lower than the inlet flow rate and the pit gain would decrease before the gas moved to the wellhead.The variation trend of the wellhead backpressure was consistent with that of the pit gain.When the gas-liquid mixture passed through the choke,the expansion or compression of the gas caused part of the choke pressure drop to be supplemented or unloaded,delaying the response rate of the wellhead backpressure.The wellbore temperature,borehole diameter and seawater depth had different effects on outlet flow rate,pit gain and wellhead backpressure.This research could provide a new idea for well control methods in deepwater managed pressure drilling.

Temperature prediction model in multiphase flow considering phase transition in the drilling operations

The study considers gas compression properties,gas slippage,back pressure(BP),phase transition(PT),well depth,and differences in gas-liquid physical properties.A new temperature model for multiphase flow is proposed by considering phase transition in the drilling process.The mathematical model of multiphase flow is solved using the finite difference method with annulus mesh division for grid nodes,and a module for multiphase flow calculation and analysis is developed.Numerical results indicate that the temperature varies along the annulus with the variation of gas influx at the bottom of the well.During the process of controlled pressure drilling,as gas slips along the annulus to the wellhead,its volume continuously expands,leading to an increase in the gas content within the annulus,and consequently,an increase in the pressure drop caused by gas slippage.The temperature increases with the increase in BP and decreases in gas influx rate and wellbore diameter.During gas influx,the thermal conductivity coefficient for the gas-drilling mud two phases is significantly weakened,resulting in a considerable change in temperature along the annulus.In the context of MPD,the method of slightly changing the temperature along the annulus by controlling the back pressure is feasible.

Research on remote intelligent control technology of throttling and back pressure in managed pressure drilling

In order to reduce the non production time of drilling,improve the efficiency and safety of drilling,improve the economic effect of managed pressure drilling(MPD),and realize the intelligent control construction of digital oilfield.Based on the pressure control in MPD,this paper analyzes the pressure control drilling system,takes the wellhead back pressure as the controlled parameter,calculates the mathematical model of the throttle valve according to the characteristics of the throttle valve,the basic parameters and boundary conditions of pressure control drilling,and puts forward an improved particle swarm Optimization PID neural network(IPSO-PIDNN)model.By means of remote communication,VR technology can realize remote control of field control equipment.The real-time control results of IPSO-PIDNN are compared with those of traditional PID neural network(PIDNN)and traditional Particle Swarm Optimization PID neural network(PSO-PIDNN).The results show that IPSO-PIDNN model has good self-learning characteristics,high optimization quality,high control accuracy,no overshoot,fast response and short regulation time.Thus,the advanced automatic control of bottom hole pressure in the process of MPD is realized,which provides technical guarantee for the well control safety of MPD.

Modern Shale Gas Horizontal Drilling： Review of Best Practices for Exploration Phase Planning and Execution

The challenging characteristics of shale formations often require horizontal drilling to economically develop their potential. While every shale gas play is unique, there are several best practices for the proper planning and execution of a horizontal well. In planning a horizontal well, the optimal method and technology for building inclination and extending the lateral section must be determined. Properly specified logging-while-drilling tools are essential to keep the wellbore within the target formation. Planning must also focus on casing design. Doing so will help ensure stability and enable reliable and productive completions. Shales pose a challenge for these elements of well planning due to their thin strata and potentially low mechanical competence when foreign fluids are introduced. Once a plan is developed, executing it is even more important to prove a viable exploration program. Fast, efficient drilling with wellbore control and minimal torque and drag should be the priority. This may be achieved by focusing on fluid hydraulics and rheology and bottom hole assembly. Managed pressure drilling (MPD) will help fast drilling, well control and stability. If MPD can be combined with new generation rotary steerable systems that allow the drill string to maintain rotation, impressive efficiencies are possible. Modern drilling parameter analysis represents the newest opportunity for executing shale gas horizontal wells. A method for ROP analysis to improve operational parameters and equipment selection is also proposed.

深水控压钻井隔水管系统连接作业窗口分析

深水控压钻井(managed pressure drilling,MPD)技术是深水钻井解决钻井液密度窗口较窄问题的重要钻井技术,但目前对于深水MPD隔水管系统连接作业窗口研究较少。基于欧拉-伯努利梁理论,在常规钻井隔水管数学模型的基础上,考虑管内高压及钻井液流速的影响,采用直接刚度矩阵法建立深水MPD隔水管系统理论模型,采用有限元法对理论模型进行离散并采用MATLAB软件开发MPD隔水管数值计算求解器。以南海某1600 m深水井为例,在同样的计算参数下,分别使用本文求解器与ABAQUS软件计算MPD隔水管系统的力学响应,结果表明本文求解器与ABAQUS软件计算结果吻合良好。在此基础上,开展深水MPD隔水管系统连接作业窗口分析,并研究管内高压和钻井液流速对作业窗口的影响。研究结果表明,管内高压对MPD隔水管连接作业窗口影响较大,而钻井液流速对作业窗口影响较小,MPD隔水管连接作业窗口稍大于常规隔水管连接作业窗口,从而可提高深水钻井时效。

控压钻井实时计算及控制决策方法研究

随着石油勘探开发向边缘、深部复杂地区和非常规资源发展,窄密度窗口、高井控风险等钻井问题越来越突出。对于窄密度窗口地层,控压钻井能有效降低钻井作业难度和井控风险。但现有控压系统在无井底压力测量数据条件下的计算分析能力有限,无法实现准确指导常规控压钻井和精细控压作业实时计算分析与控制决策推荐。因此,基于现场工程录井、控压实时数据,建立了自动判断控压钻井作业工况的分支判断树,实现了11种钻井工况的实时识别。从环空液固两相流动特征着手,耦合井筒压力和地层流体侵入量,建立了控压钻井过程中的环空压力分布预测模型,实现了井口回压预控值的计算、确定和推荐。在理论研究基础上,开发了控压钻井计算分析及控制决策系统,现场测试表明:控压钻井过程中可以进行井筒压力及井口回压值模拟分析、自动识别钻井工况和井下复杂,立管压力的系统计算值与实测值之间平均误差为1.88%,基于安全作业条件的井口回压预测值与实控值符合率达到89.8%,实现了基于实时工程参数的控压钻井在线计算分析与控制决策,提高了控压钻井井口回压控制的可靠性和时效性,有效指导常规控压钻井作业,并通过流程优化提升了精细控压钻井作业能力和智能化水平。

C/S架构的新型控压钻井计算模拟与控制软件

由于油气勘探开发中井下高温高压和复杂压力系统导致钻井过程面临的风险日益增大,因此迫切需要一款集工况数据模拟计算与井下复杂监测控制相结合的软件系统,助力实现安全高效钻井。为此,运用先进的控压钻井技术,实时监测井底压力、钻井液循环出入口流量差和密度等关键参数的变化,分析井下工况的变化,实现在钻井过程中井筒压力的快速、准确控制,有效降低钻井过程的安全隐患,及早发现并快速控制井下复杂情况,为形成预测、预控和快速处置的井筒安全提供支持。设计的控压钻井计算模拟与控制软件旨在从录井、PWD(Pressure While Drilling)、MWD(Measure While Drilling)、控压等设备获取钻井相关信息,建立水力学模型计算井筒压力、流量等参数。通过采用客户端/服务端网络架构,实现了多个客户端同时连接一个服务端,达到客户端数据同步的效果,经现场验证既可满足单机使用,又可方便网络连接,实现后方集中分析处理与远程操控。结果表明,该软件能准确地模拟计算各种钻井参数,保证安全高效钻井。实现了控压钻井由现场工程师处理模式转变为后方基于数据平台的模式,奠定了1个平台对N个现场控压钻井装备之间的互联互通基础,有力推动了控压钻井的智能化发展。

随机波浪及平台运动下控压钻井隔水管端部轴向位置预测方法

控压钻井(managed pressure drilling,MPD)技术是深水钻探时解决泥浆密度窗口较窄问题的重要技术。MPD隔水管端部为旋转控制头(rotating control device,RCD),其轴向位置的变化会直接影响井底压力。目前关于深水MPD隔水管端部轴向位置预测方法的文献较少。本文基于欧拉-伯努利梁理论,考虑管内高压和钻井液流速的影响,采用直接刚度矩阵法建立MPD隔水管系统动力学理论模型,采用Newmark-β积分法对MPD隔水管系统的动力学方程进行求解,并进一步开展随机波浪及平台运动下隔水管端部轴向位置的动态预测研究。以南海某1600 m水深隔水管为例进行分析,算例表明,一年一遇随机海况、管内高压为12 MPa,钻井液流速为2 m/s,钻井液密度为1600 kg/m^(3)时,隔水管端部轴向位置改变量在0.5~0.6 m之间波动;当进一步考虑平台慢漂运动时,隔水管端部轴向位置改变量在0.2~0.7 m之间波动。据此可计算得到井底压力的波动范围,从而可为控压钻井作业时井底压力的精确调控提供参考。

海洋精细控压钻井技术现状及应用

随着勘探技术的进步,不断向深部地层钻进,溢漏同存、窄压力窗口、异常高压等问题突出,往往会发生喷漏卡塌等复杂情况,这些已成为安全高效钻探面临和急需解决的难题。针对上述突出问题,考虑国内海洋钻井相比陆上钻井在地质特征、井身结构、作业模式等方面的差异,以陆上精细控压装备结构及工艺原理为基础,攻关形成了适合海洋作业的小型化、模块化、高效化精细控压装备及配套工艺,尤其在RCD系统结构、精细控压节流管汇结构、自动节流管汇回压补偿工艺等方面作出较大的优化升级,目前海洋化的精细控压钻井技术在加大推广应用,成为解决裂缝性储层、浅部大井眼钻进中的喷漏难题的有效手段之一。现场应用表明,精细控压钻井技术不仅有利于保障钻完井井控安全、减少井下复杂,而且可以大幅度降低钻井作业成本,在高压、裂缝发育、易漏失的储层钻井中具有广泛的应用前景,有助于提高勘探开发效益。

精细控压钻井技术及装备研究进展

精细控压钻井技术可使复杂地层普遍存在的井涌、漏失、坍塌、卡钻等井下复杂,特别是“溢漏同存”的窄密度窗口钻井难题得到有效解决,并提高复杂地层钻井成功率,实现安全、高效、快速钻井作业。实践证明,精细控压钻井技术越来越多地体现出常规钻井技术无法比拟的技术优势。文章介绍了精细控压钻井技术及装备的发展过程,重点介绍了笔者研究团队研发的控压钻井工况模拟装置及评价方法、精细控压钻井成套装备、集“钻、录、测”于一体的控压钻井方法以及欠平衡精细控压钻井工艺技术等核心技术,分析了精细控压钻井技术现场应用效果与适用性,提出了下步发展方向。精细控压钻井技术作为一项先进钻井技术,将是未来闭环钻井技术发展的重要基础。

智能控压钻井关键技术研究进展与展望

随着油气勘探开发快速向深层、深水、非常规等复杂难动用领域发展,涌、漏、塌、卡等井下风险显著增加,亟需研发自动化程度更高、且具有智能化操控能力的精细控压钻井技术与装备,加速由半自动化、自动化到智能化的发展进程,实现早期精准复杂工况预测,更快、更准地控制并消除钻井风险。在调研国内外控压钻井技术与装备的智能化发展现状的基础上,阐述了智能控压在智能控制、数据采集与处理等装备方面,以及井下复杂深度学习识别方法、智能决策分析软件等关键技术的研究进展,试验初步验证了其显著的技术优势,但仍有待现场充分验证与完善。建议进一步加速控压钻井技术与智能技术的跨界融合,建立支撑复杂油气高效勘探开发的智能控压钻井技术体系,助力我国油气工程技术高水平自立自强。

深水钻井井筒压力预测与控制方法研究进展

深水油气资源储量丰富,勘探开发前景十分广阔。井筒压力预测与精准控制对于提高深水油气钻井成功率及施工效率至关重要。为了避免钻井过程中喷、漏、卡、塌等井下复杂情况的发生,其关键点是对井筒压力进行精确预测,进一步采取有效的压力控制措施。以井筒压力预测模型为前提、压力控制为主线,系统阐述了深水油气钻采的单相流、多相流井筒压力预测模型以及单梯度、双梯度、多梯度控压钻井方法基础研究的新进展。结合目前井筒压力预测与控制方法的研究现状,提出了控压钻井技术的重点攻关方向,如酸性气体气侵后井筒流动规律、多梯度控压钻井新方法与配套装备、智能化钻井与井控系统等。该研究成果可以为控压钻井的理论发展与工艺设计提供一定的参考。通过对比研究国内外海洋控压钻井技术的特点、核心装备、工作原理及适应性等,明确不同控压钻井技术的优势与不足之处,综合考虑中国深水区域的地质结构、施工环境与经济效益,对控压钻井技术的发展提出相关建议。

全过程精细控压钻完井技术研究进展及展望

为解决深部复杂地层常规钻井钻、测、固、完井各阶段漏喷复杂多、固井质量差、井控风险高等难题,在精细控压钻井技术基础上,发展形成了“钻—测—固—完井”全过程精细控压钻完井技术。本文详细介绍了国内外精细控压钻完井技术的研发、应用历程及发展现状,并剖析了该技术领域的发展趋势,即向个性化/系列化、集成化/融合化与数智化/智能化发展,逐步替代传统井控设备、走向智能井控技术;并给出了智能化发展的必经技术途径,为行业井筒压力控制技术发展提供参考。

精细控压钻井在土库曼复兴气田中的应用与分析

土库曼复兴气田的卡洛夫-牛津阶地层压力极其敏感,地下裂缝、孔隙发育,钻井过程溢漏严重,且H_(2)S含量高,井控风险高,钻井难度大,通常难以钻达到设计钻井深。针对这一技术难题,土库曼引进精细控压钻井技术,通过实时监测钻井溢漏参数,优化调整钻井液密度与井口回压等技术措施,全过程维持对井底压力的精确平稳控制。精细控压成功助力3口续钻井以高质量、高效率完成作业,并创下该区块钻井液密度最低的记录,密度为1.28 g/cm^(3),平均单井漏失量减少87%,复杂处理耗时降低94%,平均机械钻速提升171%,并以最短钻井周期16.06天,实现产层一趟钻目标。此次应用,为土库曼裂缝性油藏的开发提供了技术借鉴与实践经验。

国内外新兴钻井技术发展现状

为满足勘探开发的要求,提高钻井工程效率、降低钻井成本,达到提高勘探开发整体效益的目的,国内外新兴起来了旋转导向钻井、垂直钻井、套管钻井、实体膨胀管、控压钻井和随钻测井等钻井新技术。详细介绍了国内外各种新兴钻井技术的发展状况、现场试验及应用情况,分析了各种新兴钻井新技术的技术优势及国内外的差距。最后建议我国应加快新兴钻井技术的研究和研制开发具有自主知识产权的钻井新工具,以缩小与国外先进钻井技术的差距,推动我国石油勘探开发的快速发展。

控制压力钻井技术应用研究

控制压力钻井(MPD)是已在国外得到应用的一种先进钻井技术,该技术能够解决复杂地层钻井中出现的复杂问题,提高钻井效率,降低钻井成本。介绍了MPD钻井技术的目标、优点和实现方法,加深了对MPD技术的特征及相关概念的理解,为研究和发展这一技术提供了理论基础。介绍了MPD技术的多种应用形式及其适用条件,为一口井设计与实施MPD技术的应用提供了可筛选的方案。MPD技术的应用需要配套的设备、监控系统和水力学程序相互配合才能完成,其中,配套的设备是应用MPD技术的首要条件。对MPD技术的相关设备进行了介绍,为MPD技术的应用提供了装备基础。

深水双梯度钻井技术研究进展

深水双梯度钻井技术主要包括海底泵举升钻井液、无隔水管钻井、双密度钻井等,可以很好地解决深海钻井中的技术难题。目前已发展了多个双梯度钻井系统:Conoco公司和Hydril公司的海底钻井液举升钻井系统,Baker公司和Transocean公司的DeepVision钻井系统,Shell的SSPS海底泵系统,AGR Subsea公司的RMR无隔水管钻井液回收系统,MTI公司的空心微球双梯度系统以及路易斯安那大学的隔水管气举、稀释系统。与常规钻井比较,双梯度钻井优势明显,它能以更低廉的成本、更短的建井时间、更安全的作业、更高的产量实现深水油气勘探开发,因此,双梯度钻井技术在中国深水油气开发中具有显著的优势和巨大的潜力。

控压钻井井筒压力控制技术初探

常规钻井技术钻遇压力衰竭或复杂地层时,经常遇到钻井液安全密度窗口窄,并引起漏、喷、卡、塌等井下复杂问题。控压钻井(MPD)通过控制井筒环空循环流体介质的流量与流态、井口施加压力等因素,结合环空压降模型计算,使环空压力保持在一定的范围,就可以降低甚至避免这些钻井问题,减少非钻井作业时间,提高钻井效率,降低作业成本。

控压钻井泥浆帽设计方法研究

控压钻井可以较为精确地控制整个井筒环空压力剖面,能有效解决钻井过程中出现的井涌、井漏、井塌、卡钻等多种井下故障,但在起钻之后不能仅靠调整井口回压平衡地层压力,需要注入高密度泥浆帽。为满足控压钻井起钻泥浆帽注入过程中井底压力恒定,必须设计出合理的泥浆帽密度和高度。为此,基于起下钻过程中的井筒压力控制原理和控压钻井起下钻工艺,建立了控压钻井泥浆帽密度和高度的计算模型,提出了一种维持控压钻井起钻过程井底压力恒定的泥浆帽密度和高度的设计方法,并以塔里木油田某井为例评价分析了泥浆帽密度和高度对井口回压控制的影响,并指出设计泥浆帽密度和高度时应综合考虑各种因素,在泥浆帽注入和驱替过程中实时控制井口压力,以维持井底压力恒定。