海上岩性油藏自流注水量计算新方法

A New Method to Calculate the Artesian Water Injection Rate for Offshore Lithologic Reservoir

针对目前自流注水量计算方法没有考虑多井同时生产的问题,利用等值渗流阻力法、距离反比加权法及物质平衡方程,推导了一种计算自流注水量的新方法,编制了相应计算程序,并进行了实例计算。结果表明:若生产层工作制度不发生大的变动,自流注水开始时注水量最大,后随生产层平均压力的增大逐渐减小,最后趋于稳定;为提高自流注水效果,应最大程度提高自流注水井在注入层的压力,优选渗透率高、供给压力高、流体黏度低的层位作为注入层。研究成果对同类型油藏自流注水量的计算及注水层位的优选提供了理论依据。

In order to improve the artesian water injection rate calculation without considering simultaneous production of multiple wells, a new calculation method is deduced based equivalent seepage resistance, inverse distance weighting and material balance equation. The corresponding calculation program is compiled to perform an actual calculation. Result indicates that when there is no great operation system change for the production reservoir, the water injection rate reaches peak value at the initial stage, and then gradually decrease with the increase of the average reservoir pressure and finally keeps constant. The water injection reservoir pressure should be maximized to improve the artesian water injection performance. It is recommended to take the reservoir with high permeability, high supply pressure and low fluid viscosity as the water injection reservoir. This research could provide a theoretical basis for the artesian water injection rate calculation and the optimization of the water injection reservoir in the similar reservoirs.