井打在大尺度裂缝上的缝洞型油气藏试井模型  

A Well Test Model for Wells Drilled in Large-scale Fracture of Fractured-vuggy Carbonate Reservoirs

作　　者：熊钰[1] 叶海峰 蔡明金[2] 牛新年[2] 

机构地区：[1]西南石油大学,成都610500 [2]塔里木油田分公司,库尔勒841000

出　　处：《科学技术与工程》2017年第34期49-54,共6页Science Technology and Engineering

基　　金：国家重大科技专项(2016ZX05025-001-004)资助

摘　　要：大尺度的碳酸盐岩缝洞型油气藏,常规试井分析的方法受到实际地质特征的限制,简化的模型有时不能满足求解要求。针对此问题,建立了基于线性流考虑缝洞特征尺度的井打在裂缝上的边缝洞试井解释模型,利用拉普拉斯变换和改进的Stehfest数值反演(AWG)求解并在MATLAB中编程绘制了双对数典型曲线。通过对典型曲线进行敏感性分析,得到其规律如下:溶洞半径主要影响了裂缝过渡段和溶洞响应阶段,其半径越大,在裂缝过渡段压力导数曲线形态不变但向下平移,其溶洞响应段波谷越深;储容比在更大程度上决定了溶洞弹性膨胀能量的大小,同时也影响了流体从裂缝中流入井筒的启动时间即流速,储容比越大,井储和表皮效应阶段启动时间越早,溶洞响应段波谷越深;裂缝系统渗透率与裂缝和溶洞系统渗透率之和的比值决定了流体在裂缝中的流动能力,其值越小,典型曲线向右平移,井储和表皮效应阶段的启动时间越晚。通过VB编程,利用该模型的典型曲线对塔里木油田某井的现场数据进行了拟合,其拟合效果较好,对特征参数的解释结果也比较符合该井的实际地质资料。In view of the large scale fractured-vuggy reservoirs,the method of the conventional well test analysis is limited by the actual geological characteristics,and the simplified model cannot meet the requirements of the solution. A new well test interpretation model of wells drilled in fracture of the fractured-vuggy reservoirs with the linear flow and the scale of fracture and cavity was established,and the double logarithmic curves were plotted in the MATLAB by using Laplace transform and the improved Stehfest numerical inversion. Some rules were obtained： the larger cavity radius is,the deeper trough of cavity response stage is,the pressure derivative curve keeps the same shape,but moves downward in the transition section of the fracture; the larger cave storativity ratio is,the sooner wellbore storage and skin effect starting time is,the deeper trough of cavity response stage is; the smaller the ratio of the permeability of fracture system and the permeability of fracture and cavity system is,type curve moves rightward,the later starting time is. Finally,practical software was developed and the new well test model was used to analysis one well test data in Tarim Oilfield and the explanation of well test kept the same with the results of geological model and drilling data.

关 键 词：缝洞型油藏 钻遇裂缝 敏感性分析 线性流数学模型 

分 类 号：TE344[石油与天然气工程—油气田开发工程]