页岩气开发新井型

中国缺水少地，人口众多，地形复杂，页岩气储层埋藏深、维度高、渗透率低、可改造性差。美国页岩气勘探开发常规技术---水平井加多段压裂在中国有一定的局限性，为此，提出了一种新的页岩气开发井型。它不同于传统的直井、斜井或水平井，由主井及其周围的辅助洞穴构成，其中主井用于生产排采，洞穴用于储层改造。主井完井方式为直井或斜井，辅助洞穴完井方式为分支定向井或丛式井或为两者的组合。储层改造采用低成本高效的聚能爆破等技术来代替高费用的水力压裂，采用多点建造洞穴代替多段压裂和同步压裂，以保持储层裂缝系统的连续性和有效性，进而扩大有效排采面积，降低井网密度。为模拟改造效果，在坚硬的混凝土路面进行了实验，结果表明，建造多个洞穴并震动，可以产生相互连通的裂隙，能够达到整体改善储层渗透性能的效果。

New Well Type of Shale Gas Development

China has large population with insufficient water and land and varied geomorphology, shale gas reservoir has the characteristics of deep burial, high dimension, low permeability and poor alterability.The application of horizontal well and multi-interval fracturing techniques have certain limitations in China, which are conventional techniques for shale gas develop-ment in America.For this reason, a new type of development well is proposed.Being different to traditional vertical, deviated or horizontal wells, it is formed with the main shaft and the surrounding auxiliary caves.The main shaft is designed for pro-duction, the auxiliary caves are for reservoir stimulation.The completion methods of main shaft can be vertical well or devia-ted well, the auxiliary caves are branch directional well or cluster wells and may be the combination of the two.For the reser-voir stimulation, the cost-effective cumulative blasting technology is adopted in place of the high-cost of hydraulic fracturing;taking multi-cave in place of multi-stage fracturing and simultaneous fracturing in order to keep the continuity and effective-ness of reservoir fracture system, expand the effective drainage area and reduce the spacing density.To simulate the effect of reconstruction, an experiment was carried out on the hard concrete pavement, the result shows that by a number of caves and vibration, interconnected fissures can be produced to achieve the overall improvement of reservoir permeability.