致密油注水吞吐影响因素研究及数学模型建立

Influencing Factors of Water Injection Huff and Puff of Tight Oil and Establishment of Mathematical Model

近年来,水平井压裂注水吞吐技术已成为致密油的主要开发技术。初期获得较高产量,但随着吞吐轮次的增加,出现产量递减快、油水置换效率低等问题。利用新疆吉木萨尔油田致密油资料,通过室内岩心注水吞吐实验和单井注水吞吐数值模拟研究,分析了注入量、注水吞吐时机、注入速度、吞吐轮次、焖井时间、采液速度等参数对注水吞吐采收率的影响,明确了注水吞吐影响因素依次为吞吐轮次、注入量、焖井时间、注入速度、采液速度。建立单井注水吞吐地质模型,对注水吞吐影响因素进行多元非线性拟合,首次推导出注水吞吐五参数和三参数经验公式,预测误差均在8%以内,为研究区及类似的致密油藏注水吞吐开发提供重要参考。

In recent years,horizontal well fracturing water injection huff and puff technology has become the main development technology of tight oil.In the initial stage of water injection huff and puff,higher production was achieved,however,with the increase of huff and puff times,the production decreased rapidly and the oil⁃water replacement efficiency was low.Based on the compact oil data of Jimusaer Oilfield in Xinjiang,through laboratory core water injection huff and puff experiment and single well water injection huff and puff numerical simulation research,the effects of injection volume,time of water injection huff and puff,injection speed,huff and puff times,soaking time and production speed on water injection huff and puff recovery are analyzed.The single well geological model is established,and the influencing factors of water injection huff and puff are fitted by multi⁃nonlinear function.The empirical formulas of five parameters and three parameters of water injection huff and puff are deduced for the first time.The prediction error is within 8%,which provides important reference for the development of water injection huff and puff in the study area and similar tight reservoirs.