裂缝对压裂充填井产量的影响研究与应用

在海上浅层油气资源开发中,常常遇到物性较差的弱胶结疏松砂岩储层,同时面临防砂和增产问题,需要采取压裂充填措施。考虑疏松砂岩的应力敏感性,同时考虑长期裂缝导流能力的衰减,建立端部脱砂压裂的油藏-裂缝渗流系统三维两相数学模型。求解后获得压裂充填后裂缝缝长、裂缝导流能力对产量的影响规律,根据模拟结果获取最佳的参数值。结果表明:对疏松砂岩储层进行压裂充填,其产量对裂缝长度较为不敏感,而受裂缝导流能力影响非常大;裂缝长度和导流能力增加带来的相对增产效果存在一个最高值;压裂充填形成的裂缝导流能力下降较快,但油井长期累计产量受其影响产生的下降幅度远小于导流能力自身的下降幅度。

Study on effect of fracture on productivity of frac-pack well and its application

In the development of shallow offshore oil-gas resource,often encountering the weak unconsolidated sand-stone reservoir with poor physical properties,meanwhile facing the sand prevention and increase production issues,it is need to take the frac-pack measure.Considering the stress sensitivity of unconsolidated sandstone and the attenuation of long-term fracture conductivity,it was established a three-dimensional two-phase mathematical model for seepage sys-tem in reservoir fractured by the tip screen-out fracturing.The model was resolved to study on the influence rule of length and conductivity of fractures on productivity after frac-pack.Based on numerical simulation results,the optimal parameter values were obtained.The result indicated that the production of wells in the unconsolidated sandstone reservoir after frac-pack is not sensitive to the fracture length and greatly affected by the fracture conductivity.There is a maximum value of increased production caused by the increases in the fracture length and fracture conductivity.The fracture conductivity after the frac-pack was decreased rapidly,but the decline rate of the long-term cumulative production is much less than that of the fracture conductivity.