川东北碳酸盐岩储层酸压改造复合暂堵技术研究

发布时间：2018-06-10 03:17

  本文选题：碳酸盐岩储层 + 裂缝　； 参考：《成都理工大学》2015年硕士论文

【摘要】：川东北气田海相碳酸盐岩储层具有高温高压且裂缝发育等特点,酸化改造中酸岩反应速度快、酸液滤失量大导致均匀布酸困难,难于达到深度酸化目的,因此开展了川东北酸压改造复合暂堵转向技术研究。论文以川东北元坝气田长兴组为主要研究对象,长兴组主要发育生物礁相和生屑滩相储层。据元坝地区长兴组岩样物性分析统计结果:长兴组礁滩相储层孔隙度0.23%~24.65%,平均4.0%;渗透率0.0028~1720.7187×10-3μm2;最大连通孔喉半径较小,主要分布于0~1μm之间。元坝长兴组储层储集空间类型主要为孔隙、溶洞、裂缝三大类,储层水平缝、斜缝及垂直缝在储层中均较发育,多数为半充填或张开缝。长兴组裂缝宽度大都在1mm左右,但个别井次也出现大型的漏失。长兴组储层具无水敏、弱碱敏(临界p H值10.5)、强应力敏特征。元坝地区长兴组属礁滩体控制的岩性圈闭气藏,气藏埋藏深度较大(6200~7200m),含气幅度较高;属正常温度、常压、高含硫化氢、二氧化碳气驱气藏或局部气水同驱气藏。根据元坝地区实验样品测试,海相地层岩石抗张强度介于0.71~5.09MPa,平均2.90MPa。地层整体弹性模量分布范围在7.11~32.81GPa之间,平均为26.44GPa;泊松比分布范围在0.20~0.47之间,平均为0.26;地层条件下抗压强度分布范围在116.94~426.32MPa之间,平均为225.81MPa;抗张强度分布范围在0.08~10.04MPa之间,平均为5.24MPa。长兴组最大水平地应力平均在2.90~3.36MPa/100m,最小水平地应力平均在2.01~2.21MPa/100m。地应力状态属典型走滑地应力模式。针对元坝长兴组气藏储层特征及完井投产管材的使用情况,进行高温胶凝酸酸液和高温压裂液性能评价。研发了高温高压酸化暂堵仪,优选了暂堵纤维与暂堵颗粒,进行了针对不同尺寸裂缝的复合暂堵技术研究,最后通过酸液与复合暂堵技术现场应用技术分析,最终设计形成了较完善的川东北储层酸压改造复合转向技术。研究结果表明:长兴组礁—滩相属孔隙型、裂缝—孔隙型储层,以Ⅲ类储层为主,少量Ⅰ、Ⅱ类储层。研制的高温高压酸化暂堵仪能够较好地模拟0~6mm地层裂缝,实现裂缝暂堵、酸化及解堵效果评价;单独采用纤维暂堵剂效果不理想,而优选出纤维+颗粒复合暂堵剂能够在10MPa压力下封堵不同尺寸裂缝,并能够在设计时间内迅速酸化解堵。进行元坝长兴组碳酸盐岩储层酸化现场试验,通过试井分析、生产数据分析、施工压力曲线拟合分析等多种手段对元坝长兴组碳酸盐岩储层酸化技术进行全面评价,完善和形成元坝长兴组碳酸盐岩储层酸化技术方案。在元坝29-2井进行现场应用,第一级暂堵液入地后压力由19MPa升高到26MPa,上涨7MPa,酸化后增产倍比达到了3.33。
[Abstract]:Marine carbonate reservoir in northeast Sichuan gas field has the characteristics of high temperature and high pressure and the development of fracture. The acid rock reaction speed is fast in acidizing transformation, and the acid fluid filtration is large, which makes it difficult to distribute acid evenly, and it is difficult to achieve the purpose of deep acidizing. Therefore, the technology of complex temporary plugging and steering for acid pressure modification in northeast Sichuan was studied. In this paper, the Changxing formation of Yuanba gas field in northeast Sichuan is taken as the main research object. The Changxing formation mainly develops reef facies and bioclastic beach facies reservoir. According to the statistical results of physical properties of rock samples of Changxing formation in Yuanba area, the porosity of reef and beach facies reservoir of Changxing formation is 0.23 ~ 24.65 with an average of 4.0; permeability 0.0028 ~ (1720.7187) 脳 10 ~ (-3) 渭 m ~ (2); and the radius of pore throat of most Dalian is relatively small, mainly distributed in the range of 0 ~ 1 渭 m. The reservoir space types of Changxing formation in Yuanba are mainly pore, cavern and fracture. The horizontal fractures, oblique fractures and vertical fractures are developed in the reservoir, and most of them are half-filled or open fractures. The fracture width of Changxing formation is mostly about 1mm, but large leakage occurs in some wells. The reservoir of Changxing formation is sensitive to water and weak alkalinity (critical pH value 10.5) and strong stress sensitivity. Changxing formation in Yuanba area is a lithologic trap gas reservoir controlled by reef beach. The gas reservoir is buried in a deep depth of 6200 ~ 7200 m ~ (-1) and has a high gas bearing amplitude, which belongs to normal temperature, atmospheric pressure, high content of hydrogen sulfide, carbon dioxide gas drive gas reservoir or local gas-water simultaneous displacement gas reservoir. According to the experimental samples in Yuanba area, the tensile strength of marine strata rock is between 0.71 and 5.09 MPa, with an average of 2.90 MPa. The distribution range of elastic modulus of the whole formation is between 7.11 ~ 32.81 GPA, the average is 26.44 GPA, the distribution range of Poisson's ratio is between 0.20 and 0.47, the average is 0.26, the distribution range of compressive strength is between 116.94 and 426.32 MPA, the average is 225.81 MPA, and the distribution range of tensile strength is between 0.0810.04 MPA and 5.24 MPA. The average maximum horizontal stress of Changxing formation is 2.90 ~ 3.36 MPA / 100 m, and the minimum horizontal stress is 2.01 卤2.21 MPA / 100 m. The in-situ stress state belongs to the typical strike slip geostress model. According to the reservoir characteristics of Changxing formation gas reservoir in Yuanba and the application of completion pipe, the performance evaluation of high temperature gelling acid fluid and high temperature fracturing fluid is carried out. The high temperature and high pressure acidizing temporary plugging instrument was developed, the temporary plugging fiber and the temporary plugging particles were selected, and the composite temporary plugging technology for different size cracks was studied. Finally, the field application technology analysis of acid solution and composite temporary plugging technology was carried out. Finally, the complex steering technology of acid fracturing modification in northeast Sichuan reservoir was developed. The results show that the reef and beach facies of Changxing formation belong to pore type, fracture to pore type reservoir, mainly to type 鈪，

本文编号：2001792