Drillhole high-pressure packer permeability test for underground powerhouse in Pushihe pumped storage hydro-plant

Usually the water head of the pumped storage hydro-plant is high, generally up to 400-500 m, therefore the rock mass under the high-pressure bifurcation pipe have to bear as high as millions Pascal water pressure, in according with the requirements of high water head pumped storage hydro-plant should be 1.2 times of the water head special high-pressure packer permeability test compared with normal to test the permeability of rock and rock cleavage pressure value. The test results on the choice of design options often play a decisive role. Based on the engineering practice, the authors studied the drillhole high-pressure packer permeability test in the pumped storage hydro-plant's underground powerhouse, by the analysis of test results, this article offers a demonstration of the deformation of rock fracture witch under building in the condition of high-pressure water head, it provides a more detailed engineering geological background.

Experimental Verification and Research for the Distortion in the Integrated Frequency Responses of the High-Pressure Sealed Cabin and Magnetic Field Sensor

Although magnetotelluric sounding method applied to the land is advanced, there are many difficulties when it is applied to marine environment, one of which is how to lay magnetic field sensors down to the seafloor to complete measurements. To protect the magnetic field sensors from intense erosion and high pressure, suitable high-pressure sealed cabins must be designed to load them. For the consideration of magnetic measurement and marine operation, the sealed pressure cabin should be nonmagnetic and transportable. Among all optional materials, LC4 super.hard aluminum alloy has the highest performance of price/quality ratio to make the sealed pressure cabin. However, it does not mean that the high-pressure sealed cabin made using LC4 will be perfect in performance. In fact, because of its weak magnetism, the pressure cabin made using LC4 has distorting effect on frequency responses of the magnetic field sensors sealed in it. This distorting effect does not affect the use of the magnetic field sensor, but if we want to eliminate its effect, we should study it by experimental measurements. In our experiment tests, frequency sweep magnetic field as excitation signal was used, and then responses of the magnetic field sensor before and after being loaded into the high-pressure sealed cabin were measured. Finally, normalized abnormal curves for the frequency responses were obtained, through which we could show how the high-pressure sealed cabin produces effects on the responses of the magnetic field sensor. Experimental results suggest that the response distortion induced by the sealed pressure cabin appears on mid- and high-frequency areas. Using experimental results as standardization data, the frequency responses collected from seafloor magnetotelluric measurements can be corrected to restore real information about the seafloor field source.

Research of in-situ hydraulic test method by using double packer equipment

Double packer equipment for hydraulic test can be used to measure pressure of test zone directly, and it is frequently used to perform many kinds of hydraulic tests and take groundwater sample from borehole. The test method of this equipment mainly includes the test design, implementation, interpretation and synthetic analysis. By adopting the double packer equipment for hydraulic test, the parameter distribution of rock permeability along borehole can be acquired, as well as the connectivity, water conductivity and water bearing capacity of the disclosed structure and the chemical characteristics of the deep groundwater. It is a necessary method for the research and evaluation of the complex hypotonicity terrace site selection under geological conditions. This method is not only suitable for the geological disposal of high level radioactive waste, but also can be used in the site selection of underground facilities such as storage of petroleum and carbon dioxide. Meanwhile, it has a good application prospect in other hydrogeological investigation fields.

双封隔取样压力数据深入解释方法研究

双封隔器是一种地层测试测压取样工具,取样过程通常需要泵抽几小时甚至十几小时,取得地层流体样品,获得压力和流量数据,但无法真实反映地层渗透率的探测范围。利用油藏模拟软件模拟双封隔器泵抽取样过程,引入Schroeter算法和Levitan算法这两种压力/流量数据反褶积算法,反演渗透率参数波及半径从几厘米到上百米,并使用数值模拟案例验证了只利用取样完成后的压力恢复数据进行反褶积方法的准确性和合理性。该研究应用于双封隔现场测井数据,采用反褶积方法得到渗透率探测半径31m,反褶积处理后的数据可用于产能预测,对正确认识油气藏具有重要意义。

基于双重介质渗流-应力耦合模型的高压压水试验渗透参数反演

高压压水试验过程中岩体易发生水力劈裂产生裂隙,岩体内部孔隙、裂隙双重导水,渗流场和应力场相互作用,导致岩体渗透参数的时空变异性。基于高压压水试验反演渗透参数需考虑双重介质渗流-应力耦合作用下产生裂隙前后渗透系数的变化规律,利用渗流-应力耦合数值模型结合工程现场高压压水试验数据进行参数反演,计算得到不同压力阶段下灰岩岩体渗透率。主要结论如下:发生水力劈裂前,随着注液压力的增大,渗透率及孔隙水压力在不同压力阶段之间分界明显,渗透率反演值与规程公式计算值相近;发生水力劈裂后,岩体渗透率增大约2倍,孔隙介质渗透率和通过的流量出现陡减现象。

气体封隔器密封单元的增强方法与安全分析

气体封隔器胶筒是实现气井分层分段开采的关键部件。常规三胶筒结构在坐封时易发生初始破坏,导致胶筒整体应力水平降低,密封安全性储备不足。为此,提出一种多材料组合式密封单元的增强方法,用于HPHT105-232-V0型含硫化氢高温高压气体封隔器密封单元的设计;基于拉伸试验和Yeoh理论获得橡胶的本构模型参数;在温度204℃、坐封力200 kN和环空压力70 MPa下,分析了胶筒的应力和变形规律;试验测试了增强单元的密封安全性。分析结果表明:HPHT105-232-V0型封隔器密封单元胶筒的最大变形量为94.785 mm,最大接触应力为240 MPa,位于金属护环与套管接触区域。根据API标准,对HPHT105-232-V0型封隔器实物进行测试试验,坐封时胶筒未发生初始破坏,密封单元的整体应力水平提高;稳压过程胶筒压降幅度小于1%;整个试验测试过程中,密封单元无气泡溢出,封隔器卸载后胶筒结构无明显的塑性变形。研究结果表明,采用该增强方法所设计的多材料组合式密封单元具有良好的密封性能,满足极端环境下的密封安全性要求。

Test and Study of the Rock Pressure Sensitivity for KeLa-2 Gas Reservoir in the Tarim Basin

KeLa-2 gas reservoir is the largest uncompartimentalized gas field so far discovered in China, with a reserve of hundreds of billions of cubic meters of dry gas. It has such features as extremely long interval (550m), high pressure (74.5MPa) and pressure coefficient (2.022). Gas reservoirs with a pressure coefficient of over 2.0 are not commonly found. The abnormal high-pressure reservoirs are quite different in characteristic and performance during the process of depletion exploitation. Therefore, it is necessary to know the property of pressure sensitivity for this abnormal high-pressure reservoir. The aim of this paper is to test the reservoir pressure sensitivity and to analyze its effect on the deliverability of gas. Through some experiments, the permeability change with the confining pressure of rock samples from KeLa-2 abnormal high-pressure gas reservoir is measured. A power function is used to match the measured data, and to derive an empirical equation to describe the change of permeability through the change of the reservoir pressure or effective overburden pressure. Considering the permeability change during the development of reservoirs, a conventional deliverability equation is modified, and the deliverability curve for KeLa-2 gas reservoir is predicted. The research indicates that the extent of the pressure sensitivity of rock samples from KeLa-2 is higher than that from the Daqing oilfield. KeLa-2 reservoir rock has the feature of an undercompaction state. The pressure sensitivity of a reservoir may decrease the well deliverability. It is concluded that for KeLa-2 reservoir the predicted absolute open flow (AOF), when the pressure sensitivity is taken into account, is approximately 70% of the AOF when permeability is constant and does not change with pressure.

Packer分层取样技术在非均质含水层勘查中的应用

在第四系松散岩层中进行抽水试验及分层取样工作一直是水文地质勘查中棘手的事情。为获得不同深度、不同层位含水层空间异质性特征,在实践应用的基础上提出了Packer分层取样结合井中物探技术,有效解决了传统钻孔抽水试验中分层抽水及取样的困难。研究表明:采用Packer分层取样技术可以实现在第四系松散岩类含水层钻孔中同径止水,分层封隔洗井、抽水试验及取样,而且易于实施,可以更加准确有效地获得空间异质性岩层中各含水层的水文地质参数。

储气库用大尺寸可溶封隔器研制及试验

在储气库不压井作业中,常规封隔器存在综合成本高、尺寸受限、溶解效果差等问题。为此,研制出一种适用于外径177.8 mm套管的大尺寸可溶封隔器。根据相关技术要求和生产需求,对该封隔器关键部件进行力学计算校核,对主体结构参数进行优化设计,在模拟地层液、KCl溶液以及柠檬酸溶液中,对配比出的镁铝合金进行室内溶解试验,并对主体结构力学性能进行仿真分析。分析结果表明:该封隔器可满足在3~15 d内储气库封隔要求,并且其溶解速率高效可控;封隔器材料溶解速率约为10~35 mg/(cm^(2)·h),溶解速度较为平稳且可控;加工样机通过室内承压试验,此封隔器可在90℃下承压40 MPa,满足现场作业要求。所得结论可为储气库大尺寸暂堵技术研究及现场作业施工提供技术参考。

裸眼测试漏失层跨式封层工具及应用

为了提升裸眼分层测试求产、分层酸化、分层注/堵水等特殊作业的技术能力,需引入新工艺技术对裸眼井段进行跨式封隔。文章主要以涠洲某探井DST测试前裸眼封层作业为例,应用裸眼膨胀封隔器等工具进行分层隔离,满足了DST分层测试作业要求,扩展了裸眼井作业的技术手段,为今后类似裸眼失返漏失层跨式封隔提供了参考和借鉴。

一种新型一次关井测试阀的研制

针对国内超深、高温、高压油气井逐步形成的“五阀一封”等地层测试工艺,在使用中存在承下压不足导致测试数据采集不合格潜在风险。通过分析RDS结构的风险引发原因,设计球阀辅助密封机构,将原有的机械动力传送改为活塞液压动力传送,设计机械自锁式辅助结构解决活塞上行问题,设计并研制了一种全新的可作为测试主阀使用的一次关井测试阀。该工具完成了室内试验,采用国产球阀,保证工具耐温、耐压满足204℃,105 MPa,球阀承下压能力由原来35 MPa提高至105 MPa。该工具可替代RDS阀使用,球阀承压不受进口球阀限制,降低了工具成本。通过配套其它测试工具,规避现有测试工艺技术潜在风险,为超深井测试提供技术保障。

基于GMS-MODFLOW的露天矿地下水流量预测数值模拟研究

某露天矿区地下水分布主要受岩体断层、裂隙等地质结构主导,开采过程中将对边坡稳定性和矿坑内排水产生影响。为预测矿区地下水量和矿坑排水条件,采用多段封隔器压水试验和变水头压水试验对岩质边坡岩体水力传导系数进行分析。在构建矿区水文地质概念模型的基础上,运用GMS软件MODFLOW模块建立了矿区岩体三维有限差分数值模型,研究了非饱和-饱和渗流模型中稳态和瞬态条件下地下水量动态变化,阐述了边坡降雨入渗导致地下水位上升和饱和区形成发展过程,分析了敏感条件下矿区地下水位分布变化,提出了按照开采深度进行不同的矿坑排水管理策略。

Packer系统在地下水勘查中的应用

在地下水勘查及研究中,准确取得多层含水系统的动力场、温度场、化学场、同位素场及参数数据,对合理概化水文地质模型、较精确的评价地下水资源,起到至关重要的作用。本文介绍了国际原子能机构(IAEA)援助中国的地下水分层试验系统(Packer系统)在B13孔勘查中取得的数据。该系统的应用将进一步推动中国在深层地下水勘查的研究。

高温高压完井封隔器结构优化

针对顺北油气田超深超高压超高温井的施工要求,设计了适用于?139.7 mm(51/2 in)套管的机械可回收测试封隔器,内通径达到50 mm。对该封隔器密封机构的变形过程及密封性能进行了有限元仿真分析,对封隔器卡瓦性能有显著影响的合金块安装间距、合金块安装倾角、合金块直径和卡瓦楔角等4个因素进行了正交试验,进而优化了卡瓦参数。优化后的卡瓦最大应力下降百分比为47.99%,应力集中现象得到了大大减弱。在理论研究的基础上开展了封隔器坐封试验、额定压差测试、绝对压力测试和封隔器解封试验。研究结果表明:该测试封隔器的强度安全可靠,可顺利完成坐封、解封,能够承受204℃以上的高温、110 MPa的额定压差及160 MPa的绝对压力,满足顺北油气田超深超高压超高温井的施工要求。

基于Arrhenius方程封隔器胶筒的寿命预测研究

为预测封隔器胶筒的使用寿命,文章将封隔器胶筒的橡胶材料的拉伸强度作为评判封隔器胶筒密封失效的依据,采用加速老化试验方法对封隔器胶筒橡胶材料寿命进行预测研究,并根据现场应用效果统计验证预测结果。首先将与封隔器胶筒同批次的四丙氟橡胶材料制成标准试样,分别在200、230、260和280℃下进行热空气加速老化试验,分析其拉伸强度与老化温度和老化时间的关系。基于Arrhenius方程原理,结合有限元分析结果和地面性能试验数据,拟合后得到退化轨迹方程,进行封隔器寿命的预测研究。研究表明:封隔器胶筒寿命与温度呈线性相关关系;应用Arrhenius方程预测封隔器胶筒寿命,其结论对现场具有较好的参考意义。

APR测试工具在高温及高压差作业条件下的改进与应用

在塔里木油田测试作业中,出现诸如封隔器胶筒高温碳化失封、“O”密封圈气爆破损渗漏、高压差失封等问题,无法安全优质地完成超深超高压高温气井的测试需要。为提升井下测试工具耐温耐压性能,基于塔里木油田“十三五”以来超深高温高压井APR测试实践,总结分析了常规高温高压井测试APR测试工具存在的问题,通过提升密封部件材料的耐温等级、优化密封组合形式、改进封隔器胶筒结构等手段,将APR测试工具的耐温耐压差性能由70 MPa/177℃提升至105 MPa/204℃。经室内高温高压评价实验,封隔器设计等级、耐温耐压等关键指标满足设计要求。现场DB×井使用改进型193.675 mm CHAMP-Ⅳ封隔器、MJ×井使用改进型127 mm RTTS封隔器,作业期间井下工具工作正常,测试均取得成功,起出检查测试工具完好。改进的APR测试工具为超深高温高压井高质量勘探开发打下了坚实的基础。

基于正交试验法的高温封隔器镶齿卡瓦优化

高温高压深井、超深井井下工况恶劣,对封隔器等井下工具性能提出了更为严格的要求。为此,以RTTS封隔器卡瓦为研究对象,结合高温井下工况开展卡瓦材料试验,运用有限元法以及正交试验设计,开展卡瓦力学行为分析。优化结果表明:井下高温条件会降低卡瓦材料力学性能,在210℃时屈服强度以及抗拉强度分别下降了9.19%和4.98%,高温下安全系数、安全裕度较常规工况应增加5%~10%;根据正交试验结果,可得卡瓦最优结构参数,即卡瓦安装间距20 mm、合金块安装倾角75°、合金块直径11 mm及卡瓦楔角8°;与原始方案对比,卡瓦最大应力由1446.1 MPa下降为752.1 MPa,卡瓦各齿咬入深度均匀性标准差由0.00305下降为0.000732。所得结论可为镶齿卡瓦结构参数优化提供理论参考。

封隔器密封胶筒挤压失效分析与改进设计

为提高封隔器的密封功能和使用寿命,设计了一种封隔器用新型密封结构。基于有限元方法和试验研究,开展了常规密封结构和新型密封结构力学分析,结果表明常规密封结构的上胶筒应力变化剧烈,特别在胶筒倒角位置应力最大,上胶筒挤压过度后易发生永久变形;新型密封胶筒应力远小于常规胶筒,且三个胶筒相互挤压变形很小,三个胶筒都在安全范围内工作,且坐封结束后三个胶筒分别与中心管和套管发生较大挤压接触,封隔密封效果较好;通过密封性能和承压试验得到新型密封结构的密封效果稳定,胶套回弹性好。研究结果可为封隔器的设计制造及现场应用提供依据。

UPP-9型笼式卡瓦高温高压完井封隔器研制

提出的卡瓦结构设计方法涵盖材料评估与选择、卡瓦组件结构优化、卡瓦结构参数优化、卡瓦测试验证等流程。应用该方法设计了可以控制启动载荷的上、下笼式卡瓦组件结构。结合ANSYS有限元分析、样机测试等方法,对所设计的笼式卡瓦组件进行优化设计与试验验证。对带有防挤出护肩的2种胶筒密封组件的试验研究表明,带隔环的三胶筒结构更为优异。在此基础上,研制了高温高压液压坐封永久式封隔器,额定工作压力68.94 MPa(10000 psi),额定工作温度204.4℃(400℉)。测试结果表明,所研制的封隔器符合API SPEC 11D1标准V0级测试要求。

高含水期井下分层采油管柱封隔器压力测试技术创新

井下封隔器装置是油气井设备系统的关键部件。由于目前注水技术较差,导致压力测试结果难以达到预期效果。研究利用三维有限元分析确定数据状态,分析当采油管处于压裂状态下,不同管柱的压力分布状态,通过分层分析建立关注封隔压力预测模型,计算得出密闭空间内的环空压力、流体介质由于温度影响及外界压力影响的总体积变化,得出封隔器内环空压力。利用数值建立有限元分析模型,对高含水期井下分层采油管柱封隔器进行压力测试。实验结果表明,本文提出的高含水期井下分层采油管柱封隔器压力测试方法具有很强的测试能力,测试结果准确率高达99%,对于实际应用有积极的意义。