多层致密油气藏分层压裂井裂缝非均匀导流能力试井分析方法  

Well testing analysis method for non-uniform fracture conductivity of multi-layer tight oil and gas reservoirs in multi-layer fracturing well

作　　者：张锦锋 吴磊磊 史文洋 张城玮 宋佳忆 汪洋[3] Zhang Jinfeng;Wu Leilei;Shi Wenyang;Zhang Chengwei;Song Jiayi;Wang Yang(Jingbian Oil Production Plant,Shaanxi Yanchang Petroleum(Group)Co.,Ltd.;Changzhou University;State Key Laboratory of Petroleum Resources and Prospecting,China University of Petroleum(Beijing))

机构地区：[1]陕西延长石油(集团)有限责任公司靖边采油厂 [2]常州大学 [3]中国石油大学(北京)油气资源与探测国家重点实验室

出　　处：《中国石油勘探》2023年第5期145-157,共13页China Petroleum Exploration

基　　金：国家自然科学基金项目“致密油藏注水诱发微裂缝机理及反演方法”(11872073);国家科技重大专项“丛式水平井井网优化设计与产能预测新技术”(2017ZX05009-003)。

摘　　要：压裂直井和多级压裂水平井是致密油气藏目前研究的主要井型,鲜有研究多层致密油气藏分层压裂井合采时非均匀导流能力裂缝参数解释问题。针对多层致密油气藏分层压裂工艺,摒弃致密储层传统压裂缝导流能力均匀的假设,考虑分层压裂缝扩展差异性引起的压裂缝导流能力不均匀现象,通过Laplace空间变换、Duhamel叠加原理和Stehfest数值反演方法,建立了具有非均匀导流能力压裂缝的多层致密油气藏分层压裂试井分析模型,研制了识别多层致密油气藏分层压裂井流动特征的试井分析图版,分析了井筒储集系数、裂缝表皮系数、压裂缝导流能力分布特征、储层物性等对油气渗流规律的影响。结果表明:多层致密油气藏分层压裂储层的油气渗流可分为5个阶段,早期流动阶段受井筒储集系数和裂缝表皮系数影响,中期流动阶段受压裂缝长度及导流能力控制;在相同生产压差下,增大各层压裂缝长度和导流能力有利于提高油气井产量;忽略压裂缝导流能力和压裂缝扩展的非均匀现象,将低估压裂缝区域压力损耗、高估压裂生产井早期产能。通过实例井试井解释,获取了各层裂缝参数。Fracturing of vertical well and multi stage fracturing of horizontal well are the two main methods for developing tight oil/gas reservoirs,but few studies have focused on fracture parameter interpretation with non-uniform conductivity of multi-layer tight oil/gas reservoirs in multi-layer fracturing and commingling production wells.Therefore,the non-uniform conductivity of hydraulic fractures caused by differential fracture propagation during multi-layer fracturing is considered rather than the traditional scenario of uniform fracture conductivity of tight reservoirs.The well testing analysis model for non-uniform fracture conductivity of multi-layer tight oil/gas reservoirs in multi-layer fracturing well is established by using Laplace spatial transformation,Duhamel superposition principle and Stehfest numerical inversion method.In addition,the well testing type curve analyzing the flow regimes in multi-layer fractured well is researched and the influence of several factors on fluid flow laws is determined,including the wellbore storage capacity,fracture skin factor,fracture conductivity and reservoir properties.The results show that:(1)The fluid flow in multi-layer tight reservoir in multi-layer fracturing well is divided into five stages,in which the early flow regime is affected by wellbore storage capacity and fracture skin factor,and the mid-term flow regime is controlled by hydraulic fracture length and conductivity;(2)Given the same production pressure difference,the larger fracture length and higher fracture conductivity are beneficial to increase well production;(3)The pressure drop in hydraulic fracture zone will be underestimated and the early well production capacity will be overestimated if fracture conductivity and non-uniform fracture propagation are ignored.Finally,a case study of well testing interpretation is given and the hydraulic fracture parameters of each layer are obtained.

关 键 词：致密油气藏 分层压裂 多层合试 裂缝导流能力 试井分析 

分 类 号：TE348[石油与天然气工程—油气田开发工程]