强制闭合条件下拟三维压降分析新模型  

A NEW PSEUDO-THREE-DIMENSIONAL DRAWDOWN ANALYSIS MODEL IN FORCED CLOSURE CONDITIONS

作　　者：王腾飞[1] 胡永全[1] 赵金洲[2] 

机构地区：[1]西南石油大学石油工程学院 [2]西南石油大学"油气藏开发及地质"国家重点实验室

出　　处：《天然气工业》2006年第1期95-97,共3页Natural Gas Industry

基　　金：国家"863"项目"石油勘探开发分布式集成应用系统"中的成果之一(编号:863306ZT04033)。

摘　　要：文章针对大量的气井压裂后立即放喷的事实,以物质平衡理论和相关分析模型为基础,建立了强制闭合条件下拟三维压降分析模型。该模型引入了滤失高度,综合考虑了产层与上下隔层之间的应力差异,能更好地模拟地层实际情况,从而获得较为准确的参数解释;首次使用压力导数进行曲线拟合,由于放大了压力变化的幅度,闭合前后呈现出明显不同线性关系,进而利用这两种线性关系的交叉计算闭合压力、滤失系数,从而进行压降分析解释更具有简便、直接、准确的特征;考虑了压裂后立即放喷对裂缝参数解释的影响,具有现场实用性,同时也适用于裂缝自然闭合情况;采用VisualBasic6.0编制了相应的解释程序,最后根据现场实例验证了该模型的正确性以及所编制程序的合理性。In view of the fact that many gas wells often blowout immediately after fracturing, a pseudo-three-dimensional drawdown analysis model in forced closure conditions is built based on the material balance theory and correlation analysis model. Filtration height is introduced into the model and the stress contrast between pay zone and the upper and lower barriers is comprehensively taken into consideration, so that the real situations of the formation can be better simulated and more accurate parameter interpretations can be achieved. Pressure derivatives are used, for the first time, to perform curve fitting. Because the amplitude of pressure variation is enlarged, the linear relationships are different before and after closure. The crossover of the two linear relationships is used to calculate closure pressure and filtration coefficient. Drawdown analysis and interpretation with this model is more simple, straightaway and accurate. As the influences of blowout immediately after fracturing on fracture parameter interpretation are taken into consideration, this model has field practicability and is also applicable to natural closure of fractures. The relevant interpretation software is programmed with the Visual Basic6.0. A field case is presented to illustrate the accuracy of the model and the rationality of the software programmed.

关 键 词：压裂 放喷 压力降 曲线拟合 闭合压力 数学模型 

分 类 号：TE357[石油与天然气工程—油气田开发工程]