苏里格气田压后评估分析

发布时间：2018-03-28 14:02

本文选题：低渗气藏　切入点：试井解释　出处：《西南石油大学》2015年硕士论文

【摘要】：国内大部分低渗致密气藏需要经过压裂才能达到工业开采的要求,而压裂效果的好坏一直是人们普遍关注的问题。本文以苏里格气田压裂气井为研究对象,结合地质学、渗流力学、数值模拟及数理统计等多个学科,对苏里格气田进行压后评估分析,完成的工作和取得的主要成果如下： (1)分析了苏里格气田的储集岩性特征、储集空间特征、储层物性特征、流体性质、温度和压力系统等特征,并对储层进行分类评价,为后续储层改造压后评估提供了基础材料。 (2)完成苏里格地区20块岩心的气水相渗实验,选择若干条有代表性的相对渗透率曲线进行归一化处理,得到能够代表不同类别储层的平均相对渗透率曲线,在此基础上分析不同类别储层相渗曲线特征。 (3)完成苏里格地区8块岩心的应力敏感实验,确定了不同类别储层的渗透率敏感系数,同时得到无因次渗透率随地层压力的变化关系。 (4)对收集到的两口井的压恢资料进行了试井解释,初步确定了压裂气井主要裂缝参数的大小和分布范围,为建立压裂气井地质模型提供依据。 (5)利用商业软件建立压裂气井地质模型,综合考虑压裂裂缝的形态特征,对压裂气井进行生产动态历史拟合,并对主要的裂缝参数进行敏感性分析,选出对压裂效果影响最大的裂缝参数。 (6)根据考虑应力敏感的压裂气井稳态产能公式,结合数值模拟历史拟合得到的裂缝半长和地层渗透率等参数,对苏里格气田20口气井的产能进行计算,并与试气报告无阻流量进行对比分析,进一步验证裂缝半长和地层渗透率的准确性。此外,分析了不同渗透率应力敏感系数对压裂气井产能的影响。 (7)应用数学理论分析方法对压裂效果进行评价,选取裂缝半长作为压裂效果的评价指标,施工参数作为压裂效果的影响因素,计算影响因素的权重和关联度,确定压裂效果影响因素的优先顺序及影响程度大小。本文在苏里格气田苏5、苏59、桃7区块储层岩石渗流实验研究及典型井压后试井解释、单井数值模拟、产能评价的基础上,确定压裂气井裂缝半长。在此基础上,通过熵权法和灰色关联分析理论对压裂效果进行评价,形成了一套简单的、系统的、适合苏里格低渗气藏的压后评价技术,为后续压裂施工设计提供理论依据。
[Abstract]:Most of the low permeability tight gas reservoirs in China need fracturing to meet the requirements of industrial exploitation, and the quality of fracturing effect has always been a common concern. In this paper, Sulige gas well fracturing is taken as the research object, combined with geology. Seepage mechanics, numerical simulation, mathematical statistics and other disciplines, Sulige gas field post-pressure assessment analysis, the work accomplished and the main results obtained are as follows:. The characteristics of reservoir lithology, reservoir space, reservoir physical property, fluid property, temperature and pressure system of Sulige gas field are analyzed, and the reservoir is classified and evaluated. 2) complete the gas-water phase permeability experiment of 20 cores in Sulige area, select some representative relative permeability curves to normalize, and get the average relative permeability curves which can represent different types of reservoirs. On this basis, the characteristics of different reservoir facies permeability curves are analyzed. 3) the stress-sensitivity experiments of 8 cores in Sulige area are completed, the permeability sensitivity coefficients of different types of reservoirs are determined, and the relationship of dimensionless permeability pressure variation is obtained. 4) well test interpretation of pressure recovery data collected from two wells is carried out, and the size and distribution range of main fracture parameters in fractured gas wells are preliminarily determined, which provides a basis for the establishment of geological model of fracturing gas wells. 5) using commercial software to establish the geological model of fractured gas wells, considering the morphological characteristics of fracturing fractures synthetically, fitting the production history of fracturing gas wells, and analyzing the sensitivity of main fracture parameters. The fracture parameters which have the greatest influence on the fracturing effect are selected. According to the steady-state productivity formula of fracturing gas wells considering stress sensitivity, combined with the parameters of fracture half-length and formation permeability obtained by numerical simulation historical fitting, the productivity of 20 gas wells in Sulige gas field is calculated. The accuracy of fracture half-length and formation permeability is further verified by comparing and analyzing the unobstructed flow rate reported by gas test. In addition, the influence of different permeability stress sensitivity coefficient on the productivity of fractured gas well is analyzed. The fracturing effect is evaluated by the mathematical theory analysis method. The fracture half length is selected as the evaluation index of the fracturing effect, the operation parameter is taken as the influencing factor of the fracturing effect, the weight of the influencing factor and the correlation degree are calculated. The order of priority and the degree of influence of the influencing factors of fracturing effect are determined. Based on the experimental study of rock seepage in Su5, Su59 and peach blocks of Sulige gas field, the interpretation of typical well pressure test, the numerical simulation of single well, and the evaluation of productivity, the fracture length of fractured gas well is determined in this paper. Through entropy weight method and grey correlation analysis theory, a set of simple, systematic and suitable post-pressure evaluation technology for Sulige low permeability gas reservoir is formed, which provides a theoretical basis for subsequent fracturing operation design.
【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】：TE37

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