超深裂缝性砂岩气层体积压裂的可行性分析  

A feasibility study on volume fracturing in ultra-deep fractured sandstone gas reservoirs

作　　者：韩秀玲[1,2] 周福建[1,2] 熊春明[1] 张福祥[3] 刘雄飞[1,2] 

机构地区：[1]中国石油天然气集团公司采油采气重点实验室 [2]中国石油勘探开发研究院廊坊分院 [3]中国石油塔里木油田公司

出　　处：《天然气工业》2013年第9期60-64,共5页Natural Gas Industry

基　　金：中国石油天然气股份有限公司科学研究与技术开发项目(编号:2010E-2105)

摘　　要：对于超深裂缝性气层由于研究及认识程度不够而难以确定合理的压裂改造工艺。为此,以塔里木盆地大北、克深气田的储层天然裂缝分布规律为基础,采用理论和室内分析以及现场实验相结合的方法进行相关研究:通过实验及地应力建模等来确定区块符合走滑应力机制;应用莫尔库伦准则分析研究天然裂缝剪切破裂机理,建立施工压力与天然裂缝孔隙压力增量之间函数关系;结合现场实例进行数值模拟,对发育不同程度的多条天然裂缝开启及扩展规律进行定量研究。结果表明:作用在天然裂缝孔隙上的压力与地面施工压力呈正相关关系,该压力增量达到临界应力值后,天然裂缝易发生剪切破坏,但无法实现全部开启;目前工况的条件下,压裂不能实现岩石本体破裂,人工裂缝只能沿着部分能够开启的天然裂缝扩展,而部分处于有利方位的天然裂缝也无法开启,天然裂缝不发育储层难以进行加砂压裂。最后,以最新研究成果优化分层压裂工艺,确定合理压裂参数,取得了较好的现场应用效果。As far as an ultra-deep fractured gas reservoir is concerned, it is difficult to determine an appropriate fracturing technology for lack of a good understanding and sufficient research at present. Based on the natural fracture distribution rules of Dabei and Keshen gas fields in the Tarim Basin, relevant studies were made by using the method combining theoretical, laboratory and field experiments; and it was determined that the block is in line with the strike-slip stress mechanism through laboratory experiments and in-situ stress modeling. The mechanism of naturally fractured shear ruptures in an ultra-deep gas reservoir was studied with Morh-Coulomb Standards and the functional relationship was established between the increased value of the naturally fractured pore pressure and fracturing pressure. Combined with field examples, numerical simulation was performed to quantitatively study the opening and extending laws of multiple natural fractures developed with different degrees. It is shown that the naturally fractured pore pressure is positive correlated with fracturing pressure on the ground and the natural fractures will present shear failures when the pore pressure reaches a critical value. However, it is difficult to make all the natural fractures open during the fracturing process. Under current working conditions, it is impossible to fracture the rock body. Instead, artificial fractures will open and extend along with some of the natural fractures. However, some natural fractures at a favorable orientation will not be opened either. Sand fracturing can not be completed in a gas reservoir with undeveloped natural fractures. To sum up, the fracturing technology of separate layers is optimized and optimal fracturing parameters are determined based on the latest research achievements. Furthermore, the research results provide guidance for field applications to achieve improved oil recovery.

关 键 词：超深气层 裂缝（岩石） 天然裂缝 剪切破坏 裂缝开启 加砂压裂 应用 塔里木盆地 

分 类 号：P618.13[天文地球—矿床学]