摘要
气顶底水油藏水平井临界产量是衡量水平井井筒是否过早水锥和气锥的一个重要因素,准确计算其大小对气顶底水油藏开发至关重要。基于水平井井筒周围气顶与底水锥进原理,考虑水平井井筒周围椭圆形等压面,并将该等压面等效为发展矩形族,利用椭圆渗流原理推导了气顶底水油藏水平井临界产量计算模型。通过实例计算与对比,本文模型计算结果与数值模拟方法临界产量计算结果相对误差为9.08%,且油层厚度较大时,两者之间的误差更小,说明本文模型准确性较好,实用性较强。敏感性分析表明,随着水平井无因次井筒位置的增大,临界产量呈现先增大后减小的趋势,且由于气水物性差异,临界产量在无因次井筒位置为0.4时取得最大值。因此,在利用水平井开发气顶底水油藏的过程中,应优选水平井井筒位置以保持较大临界产量。
Critical rate of horizontal well in gas cap and bottom water reservoirs is an important factor to measure whether the water and gas had breaked through oil-well earlier or not, so calculating its value accurately is of great significance during developing the gas cap and bottom water reservoirs. Based on the cresting mechanism of bottom water and gas cap around bore hole of horizontal well, this paper considered the ellipsoid constant pressure surfaces as family of the rectangles, used the principle of elliptical flow to deduct a new model for calculating the critical rate of horizontal well in gas cap and bottom water reservoirs. Through actual calculation and contrast, the result calculated by new model only has a small relative error with that calculated by numerical simulation method, only 9.08%. Moreover, when the reservoir thickness is big enough, the error will become smaller, which demonstrates that the new model has higher accuracy and practicability. Sensitivity analysis shows that with the increasing of dimensionless wellbore location, the critical rate presents increasing early, but decreasing when the dimensionless wellbore location has reached a high value. The critical rate gets maximum value when the dimensionless wellbore position is 0.4 because of the physical character differences between gas and water. So during developing the gas cap and bottom water reservoirs with horizontal well, it wouht be best to prefer the horizontal wellbore location so as to keep higher critical rate.
出处
《岩性油气藏》
CSCD
北大核心
2015年第1期122-126,共5页
Lithologic Reservoirs
基金
国家杰出青年科学基金项目"油气渗流力学"(编号:51125019)资助
关键词
气顶底水
水平井
临界产量
椭圆流
发展矩形族
gas cap and bottom water
horizontal well
critical rate
elliptical flow
family of the rectangles
