裂缝强制闭合时合理返排制度优选  

The Optimization of Flowing Back Velocity under the Condition of Forced Fracture Closure Technique

作　　者：杨丙秀 蒋廷学[1,2] 丁云宏[1] 汪永利[1] 孙平[3,4] 许泽君 

机构地区：[1]中国石油勘探开发研究院廊坊分院 [2]成都理工大学 [3]中国科学院渗流流体力学研究所 [4]中国石油华北油田分公司勘探部 [5]中国石油勘探与生产分公司天然气处

出　　处：《天然气技术与经济》2004年第3期60-64,80,共6页Natural Gas Technology and Economy

基　　金：国家"十五"科技攻关项目"大中型油田勘探开发关键技术研究"部分成果。

摘　　要：由物质平衡原理和流体力学原理,研究了水力压裂后不同放喷油嘴尺寸条件下,井口压力随时间的变化规律,并计算了支撑剂的回流效应和考虑干扰时的沉降距离,由此可根据不同的储层情况和压裂工艺参数条件,由井口压力大小优选合适的放喷油嘴尺寸。由模拟结果可见,井口压力越高,返排速度应越低,但随井口压力的降低,返排的速度应越高。换言之,优化的油嘴尺寸是实时的,动态可调整的。这对压后根据不同的井口压力选择相应的合理的油嘴系列,保证整个放喷返排过程中既能最大限度地提高返排率,又能最大限度地减少支撑剂的回流,提供了可靠的依据和保障,也对提高水力压裂后的效果具有重要的理论意义和现实意义。The material balance theory and fluid mechanics the- ory are utilized to establish a mathematical model of wellhead pres- sure and time under the condition of various choke size,which may be used to select the optimal choke size when using the forced fracture closure technique in a hydraulic fracturing treat- ment.After that,the proppant settlement distance is calculated con- sidering the proppant interference as a result of high proppant concentration within the fracture after the fracture closure time is worked out,What's more,the quantity of proppant flowing back from the fracture is calculated,and a judgement criterion is con- structed to calculate whether the flowing back proppant will be carried out from the bottom to wellhead according to mechanics analysis of single grain of proppant within the wellbore.On the base of above works,a figure of the settlement distance and the quantity of flowing back proppant under the condition of various choke size is worked out.The result indicates that with the in- crease of choke size,the settlement distance of proppant in fracture decreases,while the quantity of flowing back proppant increases,so that an optimal choke size may be available according to above figure.Overall,the model put forward in the paper may be used to determine the optimal choke size in order to consummate the forced fracture closure technique,hydraulic fracturing technique and production technique as well,and an idea fracturing result may be expected.

关 键 词：水力压裂 裂缝强制闭合 回流效应 干扰沉降 油嘴尺寸 确定 

分 类 号：TE357.1[石油与天然气工程—油气田开发工程]