基于不同倾角的压裂水平井试井解释

基于源函数理论,采用镜像映射和叠加原理建立了压裂水平井中裂缝呈不同角度时地层中任一点的压力计算公式,并通过Laplace变换和Stehfest数值反演得到了考虑井筒存储和表皮系数影响的水平井井底压力解.对影响水平井井底压力的因素进行研究表明:裂缝倾角对各向同性地层中的压力影响主要表现在线性流到径向流的过渡阶段;而对各向异性地层中的压力影响主要表现在早期,裂缝的倾角越大,定产量生产所需压差越大,压差变化幅度也越大;裂缝对地层的穿透程度只影响水平井各流态出现的时间,穿透程度越大,相应流态出现的时间便越晚;同时,只有当裂缝的间距达到一定距离时才能出现第一径向流,且间距越大,第一径向流持续的时间越长.

Well testing on fractured horizontal well with different dip angles

Based on source function theory, the formulas to compute the pressure of fractured horizontal well with different dip angles were established through the method of images and superposition principle, and the solutions of bottom pressure with consideration of effects of wellbore storage and skin factor were obtained by means of Laplace transform and Stehfest numerical Inversion. The effect factors of bottom-hole pressure were studied, the results show that the pressure performance influenced by different dip angles mainly appears at the transition period from first linear flow to radial flow in the isotropic formation. While in the condition of anisotropic formation, there is an influence during early-time flow period, that the bigger dip angles are, the higher differential pressure with constant production needs, and the pressure difference change increases with the growth of dip angle. The penetration degree of crack in the layer only influence the emerging time of flow behaviors, and the penetration deeper is, the later the corresponding behaviors appear. The first radial flow appears only when the fracture interspacing achieves some extent, and the larger the space is, the first radial flow lasts longer.