煤层气储层压裂水平井产能计算

PRODUCTIVITY METHOD OF FRACTURED HORIZONTAL WELLS IN COALBED GAS

煤层气作为一种重要资源 ,近多年来其研究和开发活动迅速增加。由于煤层气储层低孔、低渗特征 ,采用常规开采方法开发效果不佳。压裂技术和水平井技术是提高煤层气藏产量的有效方法。基于位势理论和叠加原理 ,建立了煤层气储层压裂水平井产能计算模型 ,考虑了煤层气储层非均质性、裂缝部分穿透储层、裂缝条数因素的影响。通过实例计算 ,分析了影响因素的敏感性。结果表明 ,煤层气产量与裂缝条数和穿透率成正比 ,每千米水平井段内合理的裂缝条数应不超过 1 0条 ;裂缝穿透率宜控制在 0 .1 5之内 ,高于 0 .1

The coalbed gas is an important resources, the activities of the research and the development are very active. The main characteristics of coalbed reservoir are low permeability and low porosity, the effect that the normal method developed coalbed reservoir is not good. The technology of fracture and horizontal well is an effective method improved output of coalbed gas. Fractured horizontal well is a potential way developed coalbed gas, applying potential function principles, superposition principal and mathematical method for solving matrix. In the process of formula derivation, many factors, such as, anisotropy of reservoir matrix, numbers of fractures, fractured on horizontal well's productivity and fully or partially penetrating in the formation and so on, were considered. Finally, in the paper the calculation example was given, and a few factors have been compared and analyzed. The results show that the relation between the horizontal well's productivity and the number of fracture is direct ratio, the suitable number of fracture is no more than 10 in the horizontal length of the well, besides, the rate of penetrating of fracture should under 0.15, if the rate of penetrating of fracture overweight 0.15, it is not sensitive that the output are affect the rate of penetrating of fracture.