浅水三角洲储层水驱波及系数定量评价

Quantitative evaluation of water flooding sweep coefficient in shallow water delta reservoir

浅水三角洲储层具有砂泥多期叠置薄互层、横向变化快的特点,开发过程中往往波及系数低,水驱效果差。本文在谢尔卡乔夫波及系数公式的基础上,针对浅水三角洲储层沉积特点,加入薄互层分布比例和砂体几何形状因素的影响,对波及系数进行定量化修正。利用此公式指导油田开发调整中的层系划分、井距优化,显著提高了该类油藏的波及系数,该评价方法在渤海湾PL油田开发调整中取得良好效果,实践证明基于纵向薄互层分布比例和砂体分布因素的波及系数定量化分析,有助于该类油藏开发政策及技术界限的制定。

Shallow water delta reservoirs are characterized by thin interlayers superimposed on sand and mud in multiple phases and rapid lateral changes.In the development process,the sweep coefficient is often low,and the water flooding effect is poor.Based on the formula of Selkachev’s sweep coefficient,the sweep coefficient is quantitatively corrected by adding the influence of the distribution ratio of thin interlayers and sandbody geometry to the sedimentary characteristics of shallow water delta reservoir.Using this formula to guide the formation division and optimization of well spacing in oilfield development and adjustment,the sweep coefficient of this type of reservoir has been significantly improved.This evaluation method has achieved good results in the development and adjustment of the PL Oilfield in Bohai Bay.It has been proved that the quantitative analysis of the sweep coefficient based on the distribution ratio of longitudinal thin interbeds and the sand body distribution factors can help in formulating of the development policies and technical limits of this type of reservoir.