摘要
根据体积压裂水平井渗流特征，将渗流区域分为A型渗流区和B型渗流区。基于线性流模型，考虑裂缝内高速非达西流现象、裂缝—井筒汇聚和污染表皮，分别建立 A 型和 B 型渗流区的渗流数学模型，并解得各模型在 Laplace 空间下的解，利用Stehfest数值反演和产量叠加原理，得到了页岩气藏体积压裂水平井的产量表达式。实际应用表明，模型能够较准确预测气井产量，且较前人的模型有更高的预测精度。研究结果表明，裂缝内高速非达西现象使气井产量降低明显，提高裂缝导流能力和增大压裂改造体（SRV）都能有效增加气井产量；在总改造体积相同的情况下，各级压裂改造体的长宽比为0.4-0.6时累计产量达到最大值，说明压裂改造时应该合理设计裂缝长度和裂缝条数；压裂改造体越大，增加压裂改造体长度减小改造体宽度或者减小缝长有利于提高气井产量；裂缝导流能力越大，减小压裂改造体长度增加压裂改造体宽度或者增加缝长能够有效提高气井产量。
According to the percolation characteristics of volume fractured horizontal wells, the whole vadose region is divided into type A and type B. Based on linear flow model, by the consideration of high speed non-Darcy flow in fractures, pollution skin and converge flow of fracture and wellbore, percolation mathematical models for the two vadose regions are established, and the solution of every model through Laplace transformation is obtained, in addition, by Stehfest numerical inversion and production superposition principle, the production expression of fractured horizontal wells in shale gas reservoir is got. The application shows that, high speed non-Darcy flow decreases cumulative production significantly in fractures, improves fracture conductivity and enlarges fracturing reconstruction volume（SRV） to increase cumulative gas production effectively. In the same condition, when the length to width ratio of each SRV is 0.4 to 0.6, the cumulative production gets maximal value, accordingly, it is important to reasonably design fracture length and number. In order to improve production, it is concluded that, the larger SRV is, the more need wants to increase its length and decrease its width or fracture length, and the greater the fracture conductivity is, the more need wants to decrease its length and increase its width or fracture length.
出处
《油气藏评价与开发》
CSCD
2016年第5期72-77,82,共7页
Petroleum Reservoir Evaluation and Development
基金
国家油气科技重大专项"高压水侵气田高效开发机理及高压气井压力系统监测方法"(2011ZX05015-002)
