Research of Extent of Well Control of Explored Reserves of Lithologic Deposit in Delta Front Area

Recently the explored reserves submitted in the oil field mainly situate at the end of deposit in delta front area. During the exploitation and production, problems mainly show on lithologic deposit, for example, reserves are low and difficulty of producing is huge. Based on results of sand body dissection of dense well network of developed oil deposit, and combined with explored reserves, this article researches a relation between extent of well control and reserves precision of explored reserves of lithologic deposit in delta front area by well diluted method. This article has significant influence on objectively understanding our unexploited

A review on casing while drilling technology for oil and gas production with well control model and economical analysis

The extraction of petroleum fluids from sub-surface accumulations mandates the drilling of a well into the formation containing the accumulation.The drilling techniques have evolved over time to overcome several challenges while some of the issues still prevail with the currently used drilling practices like loss circulation,large tripping time to change bottom hole assembly,stuck pipe problems and low well bore stability,to name a few.These decrease the drilling efficiency and increase the Non-Productive Time(NPT)of this highly capitalintensive industry encouraging the Petroleum Industry to look for new technology.Casing while Drilling(CwD)is a technique of drilling which has been proven to alleviate many of the problems faced while drilling.In this method,drilling and casing of a well bore is carried out simultaneously,which improves the drilling efficiency by reducing the NPT.It has proven to be beneficial in controlling loss circulation and improving wellbore stability by‘Plastering’effect,high quality cement job and increased rig floor safety.It uses smaller rig and less fuel thereby reducing carbon footprint in the environment.This paper studies comprehensive well control and casing string design consideration.Economics encourages its application that has been discussed in the paper.A case study on the application of CwD in Malay basin for top hole drilling is presented.Finally,the paper briefly outlines the technical challenges that need attention to get better results from CwD.

Safety Control Technology of Deepwater Perforated Gas Well Testing

Due to the high difficulties, high investment, and high risks in deepwater oil and gas well testing, major safety problems can occur easily. A key to prevent accidents is to conduct safety assessment and control on deepwater testing and to improve the testing technology. The deepwater of the South China Sea has some special environmental features: long distance from offshore, frequent typhoons in summer and constant monsoons in winter, and the presence of sandy slopes, sandy ridges and internal waves, coupled with the complex properties of oil and gas reserves which bring more challenges to deepwater well testing. In combination with deepwater well testing practice in the South China Sea, this paper analyzes the main potential risks in deepwater well testing and concludes that there are risks of failures of testing string, tools, and ground processes. Other risks are gas hydrate blockage, reservoir stratum sanding, and typhoon impacts. Specific precautions are also proposed in response to these risks in the paper.

Designing of an Automatic Paraffin Controlling Device for a Beam Well

Aiming at the paraffin-deposition problem of a beam well, the automatic paraffin-controlling device is designed by making use of ratchet-pallet mechanism, cam mechanism and modern designing method. The device has four main functions： paraffin-controlling, paraffin removal, centralizing the pumping rod, and improving the safety of well tubing. This device integrates the advantages of the paraffin control, such as strong magnetic paraffin controlling and mechanical paraffin-cutting. Theoretical analysis shows that this device has fine working reliability. It turns out to be a new device which can solve the paraffin-deposition problem of a beam well economically and efficiently.

Production Characteristics and the Control Factors of Surface Wells for Relieved Methane Drainage in the Huainan Mining Area

Based on the production data of a large number of surface drainage wells in the Huainan mining area,the present study shows that four types of typical production characteristics for relieved methane wells are recognized,of which the stable type for production and gas concentration is the most dominate,as determined by a comprehensive study on the volume and concentration of drained gases, as well as the stress changes of rocks influenced by mining.Some influence factors for the productive differences of the drainage wells were also been discussed.The results indicate that protective coal-seam mining has a significant effect on overlying strata,which promotes the development of pores and fractures of coal reservoirs for methane desorption and migration;however,the production and the stability of drainage wells are affected by deformation and damage of the overlying strata.The second distribution of strata stress is caused by mining engineering,and if the stress load is larger than the carrying capacity of the extraction well,the gas production would be influenced by the drainage well that has been damaged by rock movement.Furthermore,the case damage occurs first in the weak, lithologic interface by its special mechanical properties.The stability of drainage wells and the production status are also influenced by the different drilling techniques,uneven distribution of gas concentration,and combination of gob gas and methane from the protected layer.

A population-feedback control based algorithm for well trajectory optimization using proxy model

Wellbore instability is one of the concerns in the field of drilling engineering.This phenomenon is affected by several factors such as azimuth,inclination angle,in-situ stress,mud weight,and rock strength parameters.Among these factors,azimuth,inclination angle,and mud weight are controllable.The objective of this paper is to introduce a new procedure based on elastoplastic theory in wellbore stability solution to determine the optimum well trajectory and global minimum mud pressure required(GMMPR).Genetic algorithm(GA) was applied as a main optimization engine that employs proportional feedback controller to obtain the minimum mud pressure required(MMPR).The feedback function repeatedly calculated and updated the error between the simulated and set point of normalized yielded zone area(NYZA).To reduce computation expenses,an artificial neural network(ANN) was used as a proxy(surrogate model) to approximate the behavior of the actual wellbore model.The methodology was applied to a directional well in southwestern Iranian oilfield.The results demonstrated that the error between the predicted GMMPR and practical safe mud pressure was 4%for elastoplastic method,and 22%for conventional elastic solution.

超深井自动控制压井室内物理模拟试验及结果分析

现有超深井溢流压井技术依靠手动控制节流管汇,响应速度慢,井筒压力波动大,容易引发二次溢流、漏失等复杂情况,而自动控制压井技术可实现钻井时溢流压井作业稳定控制。为此,设计了比例–积分–微分(PID)与位移双层协同反馈的自动控制方法,开发了超深井自动控制压井系统,建立了自动控制压井物理模拟试验装置,开展了恒定目标压力、连续变化目标压力、压力突变干扰等条件下的自动控制压井试验。试验结果表明,自动控制压井系统能够在30 s左右完成节流阀开度的调节,节流压力波动范围小于0.02 MPa,与手动控制压井相比,自动控制压井系统具有良好的稳定性、准确性、反应速度和抗干扰能力。研究结果为超深井复杂地层安全压井提供了理论依据。

B301试验区油井结蜡主控因素及对策

B301试验区位于H盆地,该试验区目前油井结蜡现象严重,防蜡效果较差,防蜡措施有效期较短,无法满足油井防蜡的需要,亟需找到影响油井结蜡的主控因素。针对上述问题,通过室内实验对产出液中的蜡质、胶质、沥青质和机械杂质含量进行测定。利用Olga数值模拟软件对温度、压力、流速进行模拟。研究表明:蜡质、沥青质、机械杂质含量以及温度、流速为影响B301试验区油井井筒结蜡的主控因素,影响程度强弱依次为蜡质、温度、沥青质、机械杂质、流速。研究成果可为B301试验区进一步高效开发提供理论与技术基础,为高含蜡油藏防蜡方法提供参考。

西藏谷露地热田ZK401高温地热井钻井工艺技术

谷露地热田是西藏那曲—尼木地热带上的典型水热型高温地热田,安全、经济和高效的钻井工艺技术很大程度上决定了其高温地热资源的可开发利用潜力。ZK401井是在谷露地热田实施的一口优质高产探采结合井,地层以花岗岩类为主,其岩石硬度大,机械钻速低,钻头使用寿命短。自上而下揭露多层热储,其35~41m即可揭露124.8℃中温地热流体,汽水总量约40 t·h^(-1);50~320 m揭露超过120℃的中温热储,汽水总量约30~35 t·h^(-1);320~1320 m揭露186.9℃高温热储,汽水总量高达348 t·h^(-1),具有热储埋深浅、温度高,断裂构造发育,地层出水量大的特点,高温及水侵作用致使钻井液极易失效,井喷风险大,安全钻井难。为解决上述钻井施工难点,进行了高温地热钻井关键技术研究。通过采用异形齿PDC钻头和岩石热裂提速技术,使单只异形齿PDC钻头进尺较同规格牙轮钻头提高了23%~48%,使三开井段花岗岩类地层的平均机械钻速提升至3.18 m·h^(-1)。通过优化井身结构,采用简易控压钻井技术,利用低温清水作为二开及三开钻进循环钻井液,达到了及时发现并有效保护热储层和控制井喷风险的目的;实现了ZK401井在520 m揭露186.9℃高温热储且汽水总量达348 t·h^(-1)苛刻条件下的安全、持续钻进,且非生产时间较采用常规钻井技术的邻井缩短了37%,极大地降低了钻井成本,提高了高温地热资源的可开发利用潜力。为后续该区域乃至其他地区解决高温地热井钻井施工提供参考。

沁水盆地南部煤层气地质工程一体化关键技术

沁水盆地南部煤层气资源丰富,但地质、工程条件复杂,樊庄成熟工艺技术推广邻区适应性较差,煤层气规模效益开发面临严峻挑战。为了解决沁水盆地南部煤层气“井位部署难度大、钻井周期长、裸眼井井眼易垮塌、单井产量低”等问题,开展了地质工程一体化技术攻关,形成了“三性”煤储层评价、可控水平井钻完井、分段压裂及疏导式排采等多项关键技术,并开展现场试验与推广。研究结果表明:通过地质与工程有机结合,实现了地质模型为工程技术优化提供技术支撑,工程实践不断校正地质模型,施工精度提高;水平井煤层钻遇率95%,单井钻井复杂平均减少40%,产能到位率达90%,单井平均日产量超过8000 m^(3)。

基于上覆岩层应力场和裂缝场演化的采动井套管破断特征及防控对策

准确确定出煤矿采动井套管破断特征并提出相应的防控对策,能为井筒长期稳定提供重要保障。以平顶山矿区的二1煤层及上覆岩层为研究对象,采用理论计算与数值模拟软件模拟方法,确定出上覆岩层离层段应力和位移分布规律,分析了上覆岩层高度、距工作面水平距离与应力、位移的相关性,拟合出上覆岩层高度、距工作面水平距离与应力、位移的关系式;根据研究区采动井的实际开发经验,确定出最佳布井区域下的套管主要破断类型,结合常用套管力学参数,得出“两场”演化下的套管破断位置及长度等特征;对常用的采动井局部防护技术进行总结,并提出对应的防控对策。结果表明:工作面推进过程中,上覆岩层应力呈现出“波动-线性降低”的变化规律,位移呈现出“几乎未发生变化-类双曲线型”的变化规律。最佳布井区域下的采动井套管主要以拉伸缩径和剪切破断为主,选择施加套管加强件对采动井套管进行加固。研究区地面采动井三开段采用N80套管时,需在煤层上部46 m亚关键层处、54 m软硬互层处分别加设抗拉伸套管加强件和抗剪切加强件;采用P110套管时,需在煤层上部46 m亚关键层处加设抗拉伸加强件。建议研究区地面采动井三开段均采用P110套管,增加采动井的井筒稳定性。该研究成果为平顶山矿区及相似条件下采动井预防套管破断提供了理论指导。

父母直升机教养对大学生主观幸福感的影响:自我控制和抑郁的链式中介作用

为探讨父母直升机教养与大学生主观幸福感的关系,以及自我控制和抑郁在其中的中介作用,本研究采用直升机教养量表、自我控制量表、抑郁自评量表与主观幸福感量表对948名大学生进行问卷调查。结果发现:(1)父母直升机教养显著负向预测大学生主观幸福感;(2)抑郁在父母直升机教养与大学生主观幸福感之间起独立中介作用;(3)自我控制和抑郁在父母直升机教养与大学生主观幸福感之间起链式中介作用。本研究揭示了父母直升机教养与大学生主观幸福感之间的内在机制,对大学生主观幸福感的提升具有启示意义。

塔里木盆地顺北地区顺北84X井超千米含油气重大发现及其意义

塔里木盆地顺北中部北东向走滑断裂带长期处于油气运聚富集的优势区,顺北8号走滑断裂带实钻揭示沿断裂带发育断控缝洞型油气藏,顺北84X井纵向上沿断裂带含油气高度高达1088 m,揭示断控缝洞型油气藏含油气高度大、不受现今构造高低控制。为查明断控缝洞型油气藏含油气高度的主控因素,立足顺北中部奥陶系碳酸盐岩油气藏的成藏地质条件和钻探成果,开展顺北84X井的储层、圈闭及成藏特征等石油地质条件分析,为深化断控缝洞型油气藏认识和向深层评价拓展提供支撑。研究表明:①走滑构造破碎是致密碳酸盐岩成储的关键,其储层发育深度不受碳酸盐岩地层埋深的控制,在近9000 m的埋深条件下仍发育断控缝洞型储集体;②上覆巨厚泥岩盖层顶封、两侧致密灰岩侧封、走滑断裂平面分段和纵向分层变形是形成断控缝洞型圈闭的关键;③油-源对比分析表明油气来自寒武系玉尔吐斯组烃源岩,证实了前期顺北中、东部“寒武多期供烃、构造破裂成储、原地垂向输导、晚期成藏为主、走滑断裂控富”的成藏模式的合理性。顺北84X井的发现揭示塔里木盆地超深层致密碳酸盐岩发育受走滑断裂控制,储层纵向深度大,油气充注足,超深层勘探潜力巨大。

超深断控碳酸盐岩油藏空间结构表征技术与工程实践

在积极推进深地工程的背景下,超深断控缝洞型碳酸盐岩成为油气勘探开发的重点领域,而超深走滑断裂精准解译、缝洞体内部构型建模、断控油气藏储量雕刻评估、高效井位部署及提高采收率等是制约超深领域“增储上产”的重要科学问题与技术挑战。本文基于区域应力场研究、露头剖析、三维地震解译、物模数模,全面构建了涵盖动力学、运动学、几何学,分期、分级、分性质、分带、分层的“三学五分”断裂构造解析技术,据此阐明了走滑断裂纵向分层、横向差异分段特征,揭示了走滑断裂控储、控藏、控油气富集等地质规律,发现了超深断控缝洞型10亿吨级大油田。依据动/静态资料,精细刻画了断控缝洞体内部构型,通过“井震”结合实现了断控缝洞型油气藏量化表征,形成了相应的高效井位部署、油气储量雕刻评估等技术系列,支撑了富满油田10亿吨级油气储量的发现与落实。依据断控油气藏的定量刻画结果,针对性提出了提高采收率技术对策,推动了富满5×106t大油田的高效建设,形成了超深断控碳酸盐岩“增储上产”范例,可为我国类似油气藏的开发“上产”提供借鉴。

油田井控安全风险控制技术刍议

在我国经济的可持续发展中,油井建设是核心基础设施之一。然而鉴于油田的独特性,近些年来,井喷失控事件频繁出现,严重影响了社会的稳定发展和公众的生命财产安全。基于这种情况,要求严格控制油田井控安全风险。在此基础上,首先介绍油田井控安全管理的主要特征,然后从井身结构、地表压力、开发方式与区块、员工素质水平等方面,分析了如今油田井控面临的安全风险,最后从分级安全风险防控、分级监管技术、防卡、防漏、防喷技术、井控风险的不同等级、安全钻井技术等方面,提出了相应的风险控制技术及其策略以供参考。

延安气田上古生界致密砂岩气藏井控规模研究

延安低渗致密砂岩气田具有气藏地质状况复杂,储层物性差,非均质性强,单井控制范围小、储量动用程度低、开发难度大等特点。延安气田延145-延气2-延128井区作为最早投产开发的区域,经过2012年以来的陆续开发,气井目前普遍出现产量、压力下降快等问题,为了尽可能延长气田稳产期,达到经济高效开发的目的,明确气井产能和压力变化规律、动态储量、控制规模等开发动态,对于延安气田后续开发调整方案的制定及气田持续稳产高效开发至关重要。基于生产动态数据,采用气藏工程方法,对研究区井控储量及控制规模进行了系统评价,在此基础上对气田下一步开发调整方式进行了综合建议。

Integrated risk management: a Petrobras application in offshore well construction safety to minimize critical emergency disconnections

In order to avoid mistakes and to save a great deal of time in analysis, an innovative methodology was developed that can analyze the well operations and rig characteristics involved to define the best emergency disconnect sequence （EDS） available. A solution was developed based on the characteristics of the rigs and blowout preventers （BOPs）, and six variables were considered that directly affect the choice of EDS. All possible combinations of 64 scenarios were analyzed, and the priority of choice of the EDS was defined empirically. This paper presents an approach to EDS risk management and examples of exposure time （time without riser safety margin and shear capability） for the same well, which can be lowered from 13% to 0.1%. The impact of this reduction is related to the ability of the BOP to cut some of the heavy casings, in addition to improved availability of EDS modes. This implementation opened up many possibilities for the performance of risk exposure analysis, enabling comparison of several BOP configurations of contracted rigs and selection of the best options. This innovative approach allowed a better management of the rig schedules, prioritizing safety aspects and making it possible to allocate the fleet in a systematic way.

智能敷缆连续复合管在油田水源井上的应用

某油田地表水资源贫乏,生产生活用水主要来自水源井。但因水源井受季节和地下水资源富集程度等影响,地层产水量不平稳,无法实时监测水位,深井泵易烧毁。该油田开展数字化油田和智慧油田建设以后,水源井相关参数无法读取和接入,且水源井起下管柱和动力电缆极其不便。因此研制并应用了集成动力电缆、信号电缆的敷缆复合连续管和水源井智能控制系统,能实时读取井下动液面、出口压力、井口流量、监测深井泵运行状态等数据,实现智能监控、远程控制、实时调参、缓起缓停、变频运行、干抽保护、深井泵状态调控等多项功能,同时实现了水源井智能控制,达到了节能减排的目的。

压裂后起工具段过程中的相关井控技术探讨

随着我国石油天然气勘探开发工作的快速发展,井控工作受到广泛重视,在石油天然气资源的勘探环节、开发环节等起到至关重要的作用,但是由于在实际钻井生产期间,可能会出现压裂后起工具段的井控问题,严重影响施工工作的效果。基于此,本文分析压裂后起工具段过程中的井控技术,提出技术应用的措施和注意事项,旨在为增强技术应用的效果提供助力。

顺北油气田超深井目的层测井施工技术探讨

针对顺北油气田超深井目的层测井免测率高、资料获取率低的情况,分析测井存在的难点,主要有以下四个方面:井漏造成测井井控风险高、测井仪器性能不满足施工条件、无配套测井井控操作规程以及无配套漏失井测井工艺。针对难点,从施工前准备、井控措施及测井工艺三方面着手,施工前做好井眼准备及测井施工方案准备,施工期间制定有针对性的井控应急预案,并引入仪器性能高、井控风险低的直推存储式工艺。实践表明,采用直推存储式工艺及配套方案,顺利完成了顺北油气田近100井次目的层的测井施工,测井资料获取率从2017年的31.25%提升至2022年的93.80%,为顺北油气田的地层认识与储层评价提供了可靠的测井资料保障,有助于加快油田勘探开发进度。