叠前反演在龙虎泡致密油“工程甜点”预测中的应用

Prestack elastic inversion for “geomechanical sweet spot” prediction in Longhupao region of Songliao Basin,China

1.大庆油田有限责任公司井下作业分公司,黑龙江大庆163712;2.上海波睿能源科技有限公司,上海201913;3.Elsiwave Reservoir,北京100083;4.石油工业出版社,北京100011

1.Down hole Service,Daqing Oilfield Co.Ltd.,Daqing 163712,China; 2.Shanghai Borui Technology Co.Ltd.,Shanghai 201913,China; 3.Elsiwave Reservoir,Beijing 100083,China; 4.Petroleum Industry Press,Beijing 100011,China

在松辽盆地北部高台子组致密油开发中实施水平井水力压裂是提高油井产量不可或缺的措施之一。通过水力压裂产生更多、更复杂的裂缝从而提高油井产量。产层脆性指数越大、水平应力差越小,越容易产生更多、更复杂的裂缝系统。利用全部叠前CRP道集数据开展叠前反演得到纵波速度、密度、杨氏模量和泊松比4个关键的弹性参数数据体,采用龙虎泡地区脆性计算公式由杨氏模量和泊松比计算了目的层高台子组岩石脆性指数;使用经过优化的龙虎泡地区水平主应力计算公式由纵波速度、密度和泊松比计算并预测了主要目的层高台子组水平主应力以及水平应力差。预测的研究区高三段脆性指数和水平应力差与井数据的误差较小,并应用于水平井压裂设计,3口生产井压裂后增产效果明显。

In the development of tight oil from the Gaotaizi Formation in the Northern Songliao Basin,hydraulic fracturing of horizontal wells is indispensable as a tool to increase the production of oil wells.This process achieves this by producing fractures of increasing complexity.The higher the brittleness index and the lower the horizontal differential stress,the greater the complexity of the fracture systems.Four key elastic parameters including P wave velocity,density,Youngs modulus,and Poissons ratio were obtained using the prestack elastic inversion based on the CRP gathers.The rock brittleness index of the target formation was calculated using the brittleness calculation formula with the Youngs modulus and Poissons ratio of the Longhupao region.The horizontal principal stress and horizontal differential stress of the oil zone in Gaotaizi Formation were predicted using the optimized horizontal principal stress calculation formula with P wave velocity,density,and Poissons ratio in the Longhupao region.The prediction error for the brittleness index and differential stress was small.The predicted brittleness index and differential stress were applied to the fracturing design of horizontal wells,which increased the oil production of three production wells post fracturing.

国家科技重大专项“松辽盆地致密油开发示范工程”(2017ZX05071)资助。 This research is financially supported by the National Science and Technology Major Project of China (Grant No.2017ZX05071).

10.3969/j.issn.1000 1441.2020.01.013