低渗透油藏仿水平井注采井网产能

Productivity of the imitation horizontal well pattern in low permeability reservoirs

仿水平井技术可大幅度增加单井泄油面积和控制储量,实现了低丰度、特低渗透油藏的有效动用。为比较该技术与传统水平井技术开发效果的不同,对仿水平井不同开发井网稳态产能进行精确快速预测,以仿水平井渗流特征为基础,基于流管流线积分方法建立了不同井网形式考虑启动压力梯度的仿水平井产能预测模型。与实际产量对比表明,所建立产能预测模型得到的计算结果具有较高的准确度(最大误差为8.04%)。通过应用所建立模型进行计算对比可知,仿水平水井长度相同时,交错井网稳态产能大于正对井网稳态产能,波及面积较大,开发效果较好,而且正对井网对水井长度的敏感性大于交错井网。该研究对特低渗透油藏仿水平井井网注水开发具有一定的理论指导意义。

Imitation horizontal wells can significantly enlarge single well drainage area and increase controlled reserves, thus effectively develop low-abundance and ultra-low permeability reservoirs. In order to accurately and rapidly predict steady-state productivity of various imitation horizontal well patterns, deliverability prediction models with start-up pres- sure being taken into consideration were established for different imitation horizontal well patterns by using stream tube flow line integral method based on seepage flow characteristics of imitation horizontal wells. Comparison of the modeling results with actual production shows that the models are accurate in productivity prediction with an error less than 8.04 % only. The models also show that staggered well pattern is better than cross well pattern in terms of steady-state productivi- ty and sweep area when the lengths of the imitation horizontal well are the same. The latter is also more sensitive to well length than the former. The study may help theoretically guiding the application of imitation horizontal wells in ultra-low permeability reservoirs.