摘要
页岩气井压裂后初期产量高，随后产量迅速递减，但在预测页岩气压裂水平井产量时，目前国内尚无实际产量递减规律可借鉴。为此，进行了2.5和1.0kg/m2两种铺砂浓度下的长期导流能力试验。试验结果表明，支撑剂的嵌入及破碎导致前2d导流能力约降低43％，4d后导流能力则降低得很少。将试验结果应用到川东南某井数值模拟中，恒定导流能力方案产量为考虑长期导流能力方案的2～3倍；10年生产动态预测结果显示，示例井生产周期可分为3个阶段，前2年产量递减率高达42％～46％，第3～4年产量递减率降至27％～37％，第5～10年产量递减率缓慢降至4％以下。研究结果表明，页岩支撑剂评价优选应以裂缝长期导流能力试验结果为基础，考虑裂缝长期导流能力影响的产量递减规律可为页岩气压裂水平井重复压裂时机的确定提供依据。
Production of a horizontal well in shale gas reservoir is high initially after fracturing ,but de-clines rapidly later .T here is no practical decline profile that can be considered to predict such production in China now .In this background ,experiments of long-term flow conductivity were conducted with sanding concentration of 2.5 kg/m2 and 1.0 kg/m2 respectively .Results showed that the conductivity declined ap-proximately 43% in the first 2 days due to proppant embedding and crushing ,and at lower rate 4 days af-ter .The experiment results were used in the numerical simulation of a well located in southeast of Sichuan ;the production in the fixed-conductivity case was considered 2 or 3 times of that in the long-term flow con-ductivity case .Ten-year performance prediction demonstrated that the production cycle of sample well could be divided into 3 stages ：year 1 2 ,w hen the decline rate could be 42% 46% ,year 3 4 ,w hen the de-cline rate was stabilized within 27% 37% ,and year 5 10 ,when the decline rate was lowered to 4% or less . It was therefore concluded that proppant for fractures in shale reservoirs should be evaluated and selected using the results of long-term flow conductivity experiments ,and the production decline profile can be con-sidered to determine the re-fracturing time for fractured horizontal wells in shale gas reservoirs .
出处
《石油钻探技术》
CAS
CSCD
北大核心
2014年第5期37-41,共5页
Petroleum Drilling Techniques
基金
中国石化科技攻关项目"涪陵区块页岩气层改造技术研究"部分研究内容
关键词
页岩气
水平井
导流能力
产量递减
数值模拟
shale gas
horizontal well
flow conductivity
production decline
numerical simulation
