低渗透裂缝性煤层气储层压力敏感性研究

近年来,随着煤层气开采技术的进一步发展,国内煤层气开发已具有一定规模。由于煤层气储层具有低渗透裂缝性的特征,压力敏感性强,导致钻井过程中容易造成储层损害。因此,开展低渗透裂缝性煤层气储层的压力敏感性研究具有重要的意义。结合山西沁水盆地某区块的煤心,分别开展了煤岩受围压和孔隙压力条件下的压力敏感性实验研究,分析了煤岩渗透率随围压和孔隙压力的变化规律,探讨了孔隙压力和裂缝宽度的内在联系,认为围压增大和孔隙压力降低都会导致煤岩裂缝宽度变小,造成煤层气储层渗透率降低。

Research on the pressure sensitivity for low permeability fractured coalbed methan reservoir

in recent years,domestic coalbed methan development has a certain scale with the further development of coalbed methan mining technology.Due to the coalbed methan reservoir has the characteristics of low permeability fractured and strong stress sensitivity, the reservoir damage is easily caused in the process of drilling.Therefore, it has practical significance to carry out the research on the pressure sensitivity for low permeability fractured coalbed methan reservoir.Combined with the coal rock from the basin of Shanxi Qinshui,the experimental research on the pressure sensitivity was carried out under the condition of confining pressure and pore pressure,and analyzes the change law of permeability changing with the confining pressure and pore pressure, discusses the internal relations of pore pressure and fracture width, and thinks that increasing confining pressure and pore pressure will lead to coal fracture width decreases, cause the coalbed methan reservoir permeability decreases, the conclusion has strong guiding significance for designing the drilling and completion plan and protecting the coalbed methan reservoir.