底水厚度影响下的水平井开发规律研究

为了研究底水油藏水平井开发过程中底水厚度对开发效果的影响,通过数值模拟的方法,开展了底水厚度对底水油藏开发影响的规律研究,并建立了不同流体性质、不同油层厚度对应的临界底水厚度图版,提出了考虑底水厚度影响下油层厚度布井下限值确定思路。研究结果表明,临界底水厚度与油层厚度呈较好的线性关系,原油黏度越小,特征曲线斜率越大,底水厚度影响越大;当底水厚度低于临近底水厚度时,底水厚度越小,单井累产油指标越高。以地层原油黏度30 mPa·s、累产油4×10⁴ m³为经济极限累产油为例,针对底水厚度3 m的区域,相比常规界限认识,油层厚度下限值降低1.5 m即可满足布井条件。该研究成果对低油柱薄层底水油藏的进一步挖潜及调整井优化部署提供一定的指导意义。

Study on development law of horizontal wells under the influence of bottom water thickness

In order to study the influence of bottom water thickness on the development effect by horizontal wells in bottom water reservoir,the law of the influence of bottom water thickness on the development of bottom water reservoir was studied by numerical simulation,and the critical bottom water thickness chart corresponding to different fluid properties and different reservoir thickness was established,the method of determining the lower limit of oil column height considering the influence of bottom water thickness was put forward.The result of research shows that a good linear relationship between the critical thickness of bottom water and the thickness of reservoir.The smaller the crude oil viscosity,the greater the slope of characteristic curve,and the greater the influence of bottom water thickness.Based on the formation crude oil viscosity of 30 mPa·s and the economic limit of cumulative oil production of 4×10⁴ m³,for the area with bottom water thickness of 3 m,the lower limit of oil column height could be reduced by 1.5 m to meet the well layout conditions compared with the conventional limit.The research results provided some guiding significance for further tapping the potential of low oil column thin bottom water reservoir and the optimal deployment of adjustment wells.