Well Hutan 1 is an ultra-deep well with high pressure and high temperature.To address the challenges posed by complex geological conditions,adverse well conditions,and extreme operational conditions during the well testing process,a risk assessment of the construction was conducted.The well testing operation primarily faces three potential risks:pipe sticking in the well,well safety and well control risk.Innovative measures were taken to mitigate these risks.An integrated pipe string,optimized for perforation and testing,was used to avoid the risk of pipe sticking in the well.On the base of well safety check,sand production prediction and casing pressure control calculation,the maximum casing pressure limit was set,and the production pressure difference was controlled on-site,eliminating well safety risk.Through optimization of surface testing processes,real-time tracking and analysis as well 000 emergency measures,well control risk was effectively controlled.The safe and smooth well testing operation in Well Hutan gained a high-yield industrial flow of oil and gas,with daily gas production of 61×104 m3 and daily oil production of 106 m3,the recorded reservoir pressure reached an impressive 146.07 MPa.The research results provide technical reference for oil testing in high-temperature,high-pressure and ultra-deep wells.

准噶尔盆地南缘西段清水河组储层埋藏深、高温、高压,基质物性差,试油与压裂改造时受到超高地层压力、超高地层破裂压力、井身结构、管柱及工具结构等因素限制,储层改造不充分.为此,基于南缘西段深层高压油井储层特点,采用环空替入加重液降套压、前置液顶替加重液防超压、油套双流程控压等技术措施,形成了"光油管"试油压裂一体化工艺,其具有降低工具失效风险、可有效监测套压和提高施工安全系数等优点."光油管"试油压裂一体化工艺在南缘西段超深、超高压井应用了 5 井次,工艺实施成功率 100%,测试成功率 100%,其中高泉 6 井压后日产油量 126.81 m3,日产气量 8300 m3.该工艺有力支撑了准噶尔盆地南缘区块深井、超深井的安全高效试油、压裂,可为同类型井的应用提供借鉴与指导.

尾管固井完井技术已成为深井、超深井、复杂结构井中不可缺少的完井方式之一,其中评价尾管悬挂器的安全可靠性是井筒完整性的重要内容和难点.为了建立一套适用于深层、超深层高温高压井尾管悬挂器安全性评价方法,以新疆南缘超深高温高压地LX1井尾管悬挂器为研究对象,基于非连续介质的非线性接触问题的有限元原理及其方法,建立了LX1井尾管悬挂器安全性评价方法及其液缸外壁压力预测的有限元新模型.研究结果表明:①模型中地层—水泥环、水泥环—套管、套管—水泥环以及水泥环—悬挂器液缸等,其相互界面之间全部用的接触力学有限元模型,边界条件包括地应力、井筒内压以及悬挂器双卡瓦内由下部尾管悬重产生的预拉应力,地层岩石及其水泥石的材料模式采用岩石力学中的DP破坏准则;②该模型可以直接获得接触界面之间的接触压力,能够准确和定量模拟计算从地层传递到悬挂器液缸外壁的压力,解决了以前的模型无法直接获得各界面的传递压力问题;③该模型评价了极端工况下183 MPa内压下,按API 6X规范的材料第三强度理论应力线性化分类评价方法以及采用应力包络线方法,对LX1井尾管悬挂器评价结果安全,已经在该井应用中得到了验证和应用.结论认为,建立的尾管悬挂器液缸外壁压力随井筒内压变化的新方法,已经在该区的超深井得到了应用,该方法为超深高温高压井评价悬挂器的实际承压能力及其安全性评价提供了简便、可行的计算方法,有力保障了深部高压油气的高效、安全开发.

文章针对准噶尔盆地超高压井LT1井试油测试过程中存在的测试工具超压、管柱受力复杂及井控风险高等技术难题,开展了试油测试技术研究.通过管柱优化和工艺安全性评价,形成了适用于准噶尔盆地超高压井的试油测试技术.在盆地南缘LT1井应用"两阀一封"射孔测试联作技术,消减了超高压井试油测试工具超压、管柱安全系数低等风险,实测地层压力为155.42 MPa,创中石油集团地层测试最高地层压力纪录,该研究为超高压油气藏的试油测试配套工艺提供了技术借鉴.

Models for multiphase flow in embedded fractures and multi-fracture-intersecting networks were built to accurately characterize the flow of multiphase fluid in complex fractures in shale oil reservoirs. The numerical simulation method was utilized to analyze the flow law of multiphase fluids in the multi-fracture-intersecting networks. The results show that the numerical simulation method for the multiphase flow in the fracture networks solves problems such as single fluid type characterization, large fracture scales, high requirements for meshing accuracy, and discontinuity of fluid parameters at the fracture interface. This method can be used to assess the communication scale of hydraulic and natural fracturesand the distance between them. The formation pressure calculated by the numerical simulation method can be used to characterize the pressure variation near the fracture networks of shale oil reservoirs with the production time. The numerical simulation method proposed in this paper shows high efficiency in computing, and provides a new technical approach for the evaluation of shale oil reservoirs.

玛湖凹陷乌尔禾组致密砾岩油藏水力压裂裂缝形态复杂,支撑剂运移铺置规律尚不清楚,影响了储集层压裂效果.通过对不同形态迂曲裂缝进行重构,利用Fluent中的两相流模型,在考虑支撑剂与粗糙缝面相互作用的基础上,分析了砾石粒径、砾石数量以及砾石处缝宽衰减等对支撑剂运移铺置的影响.研究结果表明,砾石粒径对支撑剂运移的影响较为明显,砂堤平衡高度与砾石粒径呈负相关,平衡时间与砾石粒径呈正相关;砾石数量对支撑剂运移的影响较小,砂堤平衡时间和平衡高度与砾石数量呈负相关;砾石处缝宽衰减对支撑剂运移的影响很大,随砾石处缝宽衰减程度增大,砂堤平衡高度和平衡时间均减小.

Technical research was carried out to enhance fracture control in fracturing with tight spacing and boost longitudinal production by cross layer fracturing in thin interbeddings. The research aims to address the difficult enhancement of horizontal well production induced by low fluidity and limited fracture height in beddings of the shale oil reservoirs in Jimusaer, Junggar Basin, and improve the production in the second-class shale oil reservoirs of the lower sweet spot areas in this region. The technique of fracturing with tight spacing was studied, with the average inter-cluster spacing reduced to 13.6 m, greatly strengthening the fracture control in shale oil reservoirs. The displacement and gel amount during vertical well fracturing were increased, and the feasibility of cross layer fracturing in the second-class reservoirs of the lower sweet spot areas was verified. As a result, the key technologies of cross layer fracturing, featured by large displacement (12–14 m3/min) in horizontal wells, multi-slug pumping of gel and slick water, proppant integrating medium and small particle sizes, and large sand addition (2.7 m3/m), were developed to provide strong support against the turning fractures in beddings.The annual cumulative oil production of the horizontal test wells in the second-class reservoirs achieved 9 183 t, more than three times that of previous horizontal wells.The field test demonstrates that the technologies can enlarge the fracturing volume in horizontal wells.The research results show that the cross layer fracturing with tight spacing for horizontal wells can solve the production problem of multiple thin oil layers in the second-class reservoirs and provide a new technical approach for the fracturing production of horizontal wells in such reservoirs.

通过压力恢复数据及储层岩石特性,建立符合高探1井地层真实状况的双孔介质部分射开“U”形边界数学模型,采用Laplace变换及分离变量法对数学模型进行求解,利用Stechfest数值反演绘制出压力及其导数双对数试井曲线,对高探1井压力恢复资料进行解释分析;采用瞬时IPR曲线预测产能,采油指数高达22.73 m3/(d· MPa).结果 表明,高探1井储层物性好,压力高,污染小,具备高产且长期稳产的能力.高探1井在试油期间录取的大量动态数据,可为油气开发制度的制定提供可靠依据.

在油藏开发之前,为研究油藏类型、油藏边界、极限生产能力,进一步录取不同生产制度下的温度、压力、产量及气油比等资料,求取该井的最高极限产能,需要对油藏进行系统试井.本文以某油藏为例,针对该地区油藏高温、高压和高产的技术难点,探讨一种新型的系统试产工艺,以期可以给同行提供一定借鉴.

高探1井位于准噶尔盆地南缘冲断带四棵树凹陷高泉东背斜上,是一口高温高压、高产风险探井,该井试油测试过程存在测试工具尺寸选择受限、测试管柱在极端工况下受力复杂、地面测试流程安全风险极高等难题.针对高探1井高温、超高压、超高产的工况特征及技术难点,优化采用"三阀一封"APR射孔—测试联作管柱及140 MPa超高压地面测试流程,使用闸阀远程开关控制系统,实现井下测试管柱及地面测试流程的施工安全,并试获日产原油1213 m3、日产气32.17×104 m3的成果,录取到完整的地层参数,该井测试技术对高温高压、高产井的试油具有一定的指导意义.

高探1井试油时,井底流体温度随着产量增大而升高,而现有测试资料分析方法无法解释该现象.为此,根据质量和能量守恒方程,考虑高温流体在地层中的渗流规律和在井筒内的流动规律、渗流和流动时的传热,建立了储层和井筒的热流耦合模型,利用该模型分析了温度瞬态数据,反演了高产井地层温度.高探1井的生产压力和温度数据反演结果表明,反演得到的温度曲线与实测温度曲线吻合良好,可以解释井底流体温度随产量升高的现象.研究表明,高产井地层特征温度反演方法能够定量分析地层热力学和渗流参数、确定高产井流体的产出位置,为生产管柱安全评价、现场生产决策、油藏认识和储量计算提供了理论依据.

大规模的压裂改造会导致套管处于复杂的受力状态中,严重时会出现变形、弯曲、断裂等问题.考虑井眼轨迹、套管结构、压裂施工要求,考虑套管浮容重、管内流体压力、流体摩擦阻力以及温度载荷作用,建立套管轴向载荷力学模型.计算套管所受轴向力,分析其抗拉强度,以合理选择压裂参数,预防套管损坏.以油田某井压裂施工为例,根据建立的轴向载荷力学模型,计算得三维弯曲井眼中套管的最大轴向载荷在井口位置约为2191.648kN;井口套管抗拉强度安全系数最低,约为1.408,基本满足压裂施工要求.

准噶尔盆地玛湖凹陷百口泉组储层渗透性差,油气产量呈持续递减的趋势.对于低渗油藏非自喷井,油田现场往往需要通过抽汲的助排方式进行求产.抽汲并不是一个定流量过程,也不能简单采用多个阶梯流量来表示,且抽汲测试停捞期间相当于DST流动,而不是常规的压力恢复,常规试井分析方法无法对抽汲求产获得的试油资料进行产能分析.针对此类问题,建立了非自喷井抽汲测试求产的数学模型,采用压力历史拟合方法预测未来压力变化,通过计算停抽期间的井底压力来获得地层渗流到井筒的液体量(产量),从而实现了抽汲试采井的产能预测.将该方法应用于百口泉组F3井,结果表明,使用该方法评价和预测非自喷井的产能是可行的.

针对准噶尔盆地西北缘车排子凸起石炭系存在的储层裂缝发育、地层压力低、压裂加砂困难、返排率低等问题,基于储层高效开采目的,以石炭系重点探井储层改造为研究对象,开展综合前置液多段塞、前置液拌液氮增能及低密度支撑剂等工艺的小型测试压裂改造技术应用.CP13井现场应用研究表明,在修正的地质模型、优选施工工艺、优化施工参数条件下,经四段塞、11 m3连续泵入液氮、70/140目和30/50目陶粒等处理改造后,该井日产油最高达26.16 m3,日产气最高达0.382× 104m3,较改造前增产效果明显.小型测试压裂可以在类似低压裂缝性储层改造过程中推广应用以满足高效开发的生产需要.

In Mahu depression of Baikouquan formation with low porosity and low permeability reservoir thickness,oil and gas shows at the top.There are lithology and stress shielding layer in the underpart of the reservoir,and the fracture tends to extend downward in the fracturing,the proppant is easy deposits in the lower part of the reservoir.In recent years,for the effective use of thick reservoirs,the technology of secondary sand fracturing and soluble fiber suspension and combination of bottom laying sand control is carried out.Through the continuous improvement of reservoir reconstruction technology,the effective use of high quality reservoirs has been realized.It shows that the bottom sand laying technology of combined process and soluble fiber suspension sand technology is better than that of the secondary sand fracturing.D13 well adopts combination technology to control bottom sand laying technology,the highest daily production oil is 40.55 cubic meters per day,Nissan gas is 3070m3,that productivity test is 165 days,accumulated oil production 2083.11m3.It has realized the effective transformation of reservoir.

在压裂、酸化等注入过程中,若井筒温度场发生变化,不仅会导致注入流体的性能发生变化,井下管柱、套管也会受到"温度效应"的影响,导致管柱变形.为此我们利用能量守恒定律,建立井筒传热数学模型,并结合计算机技术,对实际生产数据进行计算求解,实现了注入过程中井筒温度场的预测,为注入作业参数的合理选择提供了理论依据.

In order to effectively control and reduce the damage of fracturing fluid to reservoir, further improve the effect of fracturing fluid and reduce the cost of fracturing, in the fracturing process of low porosity and low permeability heterogeneous reservoir of Fengcheng group of Mahu depression, because high concentration of guanidine fracturing fluid is easy to cause damage to the reservoir, meanwhile, the cross-linking of guanidine gum fracturing fluid under alkaline conditions easy happens, and the influence of high salinity on the performance of fracturing fluid is easy, modification of xanthan gum for low damage fracturing fluid has been carried out. The results of research show that modified xanthan gum can overcome the influence of alkaline environment, high salinity and boron ion; after gel breaking, the residue content is 90 mg/L, less than 56.5% of the residue content of HPG, which effectively reduces the damage to the formation caused by the broken gel liquid residue. 13 times of reservoir reformation have been carried out in the slope area, 10 wells have obtained industrial oil flow, the oil recovery rate is 55.6%, and better reconstruction results have been achieved.

The effect of reservoir stress variation on the fracture morphology is usually not considered in the simulation calculation on staged fracturing productivity of horizontal wells in low permeability and ultra-low permeability oil and gas reservoirs, leading to large calculation errors. In this paper, the 2D induced stress ifeld computation model was combined with the estimated staged fracturing time interval in each stage to calculate the effect of the existing artiifcial fractures on the stress ifeld variation and predict the artiifcial fracture morphology in subsequent fracturing. Then, based on the prediction results, a geologic model was established, and the 3D three-phase black-oil model was used to calculate the post-fracturing productivity of horizontal wells. Finally, a staged fracturing productivity computation method of horizontal wells with consideration to the stress ifeld variation in case of existence of artiifcial fractures was deifned. According to the study results, when the stress ifeld variation is considered, the artiifcial fracture morphology would change obviously, from the expected transverse fractures to T-like artiifcial fractures, and some transverse fractures would be far away from the planned perforation location. The ifeld application in the JM reservoir shows that the ifve-year cumulative production of horizontal wells obtained with consideration to the existence of 8 transverse fractures is 5.6% different from that without consideration to the stress ifeld variation. This veriifes the necessity that the stress ifeld variation should be considered in calculating the staged fracturing productivity of horizontal wells.

针对致密油气开发中的复杂裂缝 ,提出了采用PEBI网格表征水力压裂中不同类型裂缝(裂缝与水平井筒轴线垂直、裂缝沿水平井筒轴线方向 ,以及裂缝与水平井筒轴线成一定角度)的方法.基于PEBI网格及有限体积离散 ,研发了水平井多段压裂数值模拟程序 ,通过解析解验证该程序对水平井多段压裂的产能分析结果的准确性.以新疆油田某井为例 ,设计多种压裂方案 ,分别计算每种压裂方案下的产能 ,在此基础上 ,给出压裂优化方案建议.考虑到水力裂缝的时效性 ,选取一年内的产能数据 ,模拟计算了180 d生产数据 ,模拟结果与半年内实际油产量递减规律一致.