龙女寺构造异常高压气层识别

发布时间：2018-06-06 13:27

本文选题：异常高压 + 气层识别　；参考：《西南石油大学》2015年硕士论文

【摘要】：川中龙女寺气田地质构造复杂,断层、裂缝较为发育,其目的层岩性以碳酸盐岩为主,地层压力系数变化范围在1.0-1.9之间,表现为明显异常高压。本文以龙女寺构造沙溪庙-灯影组地层为主要研究对象,充分利用地质、钻井、测录井等数据,从岩石力学角度出发,重点开展地层孔隙压力预测及高压气层识别,为高压气藏的顺利钻探和高效开发提供了决策依据。主要研究内容和取得成果如下： (1)基于NCRA法开展了复杂地层岩性分析,结合取芯和岩屑录井资料建立了工区地层岩性剖面。利用电成像测井资料分析了目的层的裂缝和孔洞等空隙空间结构特征。这为异常高压气层识别提供了岩性和物性依据。 (2)传统的地层孔隙压力计算方法忽略了流体膨胀、构造挤压等因素,降低了地层压力计算的精度。龙女寺构造异常高压的主要成因是地层卸载作用,包括烃源岩生油和油裂解气两个方面。本文采用改进的伊顿法和有效应力法分别计算砂泥岩和碳酸盐岩地层的地层孔隙压力,计算结果与实测地层压力相符。工区大安寨-筇竹寺组地层呈现异常高压。 (3)利用工区关键井层段的横波时差和纵波时差数据,通过回归分析得出横波时差曲线的计算公式,据此可构建无阵列声波资料井的横波时差曲线,为岩石力学参数的计算提供了重要基础数据。 (4)根据地层含气声学特征理论,高压气层具有泊松比相对较低、体积压缩系数相对较大、流体压缩系数远远大于非气层的岩石力学特征,利用纵横波时差曲线和密度曲线准确计算对气层敏感的岩石力学参数,以试气结果为参照标准,采用两参数交会法分区、分层位建立气层识别图版,并确定了异常高压气层的判释标准。 (5)灰色关联分析法综合考虑了能够反映气层响应特征的多种参数,具有直观、便捷的优点。分别采用岩石力学参数和测井四参数、六参数的灰色关联法建立工区储层含流体类型识别的中心模式,并识别工区关键井储层含流体类型,岩石力学参数灰色关联法的识别符合率最高。 (6)结合工区的钻井和录井资料可以及时有效地识别各井的异常高压气层,高压气层有其相应的钻井技术对策,应尽可能避免在钻进高压气层过程中发生井涌、井喷等复杂事故。基于上述一系列方法与模型,形成了一套适合于龙女寺构造工区的复杂岩性分析、岩石力学参数和地层压力计算及高压气层识别的方法与技术,效果良好,可为异常高压气层的钻探和开发提供决策依据。
[Abstract]:The geological structure of Longnusi gas field in central Sichuan is complicated, the faults and fractures are relatively developed, the lithology of the target layer is mainly carbonate rock, and the variation range of formation pressure coefficient is between 1.0-1.9, which shows obvious abnormal high pressure. In this paper, taking Shaximiao-Dengying formation of Longnusi structure as the main research object, making full use of geological, drilling and logging data, from the point of view of rock mechanics, the prediction of formation pore pressure and the identification of high-pressure gas layers are emphatically carried out. It provides the decision basis for the smooth drilling and high efficiency development of high pressure gas reservoir. The main contents and results of the study are as follows: 1) based on the NCRA method, the lithology analysis of complex strata is carried out, and the stratigraphic lithology profile of the working area is established by combining the core extraction and cuttings logging data. The characteristics of void space structure such as fractures and voids in the target layer are analyzed by using the electrical imaging logging data. This provides a basis for lithology and physical properties for the identification of abnormal high pressure gas formations. 2) the traditional calculation method of formation pore pressure neglects the factors of fluid expansion and structural compression, and reduces the accuracy of formation pressure calculation. The main cause of abnormal high pressure in Longnusi structure is strata unloading, including source rock oil generation and oil cracking gas. In this paper, the improved Eaton method and the effective stress method are used to calculate the formation pore pressure of sand mudstone and carbonate rock, respectively. The calculated results are in agreement with the measured formation pressure. The formation of Da'anzhai-Qiongzhusi formation presents abnormal high pressure. 3) based on the S-wave moveout and P-wave moveout data of key wells in the working area, the formulas for calculating S-wave moveout curves are obtained by regression analysis, and the S-wave moveout curves of wells without array acoustic data can be constructed. It provides important basic data for the calculation of rock mechanics parameters. According to the theory of acoustical characteristics of gas-bearing strata, the high-pressure gas layer has the characteristics of relatively low Poisson's ratio, larger volume compression coefficient, and greater fluid compression coefficient than that of non-gas formation. The sensitive rock mechanics parameters are calculated accurately by using the longitudinal and shear wave moveout curve and density curve. Taking the gas test results as the reference standard, the gas layer identification chart is established by using the two-parameter intersection method. The standard of interpretation of abnormal high pressure gas reservoir is determined. 5) the grey relational analysis method synthetically considers many parameters which can reflect the characteristics of gas reservoir response, and has the advantages of intuitionistic and convenient. The grey correlation method with four parameters of rock mechanics, four parameters of logging and six parameters is used to establish the central pattern of reservoir fluid type identification, and to identify the fluid type of key well reservoir in the working area. The recognition coincidence rate of grey correlation method for rock mechanics parameters is the highest. 6) combined with the drilling and logging data in the working area, the abnormal high pressure gas formation of each well can be identified in time and effectively. The high pressure gas formation has its corresponding drilling technical countermeasures, and the complex accidents such as well bore and well blowout should be avoided as far as possible during the drilling of the high pressure gas reservoir. Based on the above methods and models, a set of methods and techniques suitable for complex lithology analysis, calculation of rock mechanics parameters and formation pressure, and identification of high pressure gas layers in Longnusi structural area have been developed, and the results are satisfactory. It can provide decision basis for drilling and development of abnormal high pressure gas reservoir.
【学位授予单位】：西南石油大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P618.13

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