沁端区块煤层气水平井分段压裂裂缝参数优化研究

Optimized study on fracture coefficient of sectional fracturing in coalbed methane horizontal well in Qinduan Block

为研究煤层气水平井开发中压裂参数影响因素,针对沁端区块煤层气藏条件,基于数值模拟方法,利用正交试验设计,通过极差分析,研究了该煤层气区块裂缝条数、裂缝长度、裂缝间距、导流能力、裂缝布缝规律和裂缝形态组合对压裂水平井产能的影响。结果表明：影响增产效果因素按主次顺序依次为生产压差、裂缝条数、导流能力及缝长;1 000 m长水平段煤层气水平井保持生产压差为3-4MPa、裂缝数量6-7条、裂缝间距约150 m并采用均匀布缝、哑铃构造裂缝形态开采效果最好。应用水力喷射分段压裂工艺,对Z-2H水平井U型井组进行了7级压裂施工设计,模拟施工效果良好。

In order to study the factors affected to the fracturing parameters in the development of the coalbed methane horizontal well,according to the coalbed methane reservoir in Qinduan Block,based on the numerical simulation method,the orthogonal test design was applied to study the fracture number,fracture length,fracture spacing,flow capacity,fracture distribution law and fracture morphology combination affected to the production of the fractured horizontal well. The results showed that the factors affected to the yield increasing effect would be the production pressure difference,fracture number,flow capacity and fracture length. In the coalbed methane 1 000 m horizontal well,the production pressure difference should be kept as 3 - 4 MPa,the fracture number should be 6 - 7 and the fracture spacing should be about 150 m. The mining effect with even distributed fractures and dumbbell structure fracture morphology would be the best.The sectional fracturing technique with the hydraulic jet was applied to the seven grade fracturing construction design of the U type well group in the Z-2H horizontal well. The simulation construction effect was excellent.