基于地质工程一体化的裂缝性地层漏失压力预测

Prediction of leakage pressure in fractured formation based on integration of geology and engineering

针对新探区裂缝性地层地质及工程资料严重缺乏,导致现有漏失压力计算模型有效性降低这一问题,文中提供了一套地质工程一体化裂缝性地层漏失压力预测方法,即在现有漏失压力计算模型的基础上,引入裂缝指数,结合钻井液漏失机理,制定漏失类型分类评价指标,形成裂缝性地层漏失压力三维建模方法。另外,建立了渤海A油田漏失层漏失类型分类评价指标,对A油田进行了三维漏失压力建模及预测,并在C-5井成功应用,钻井周期缩短15 d。应用结果表明,A油田的裂缝指数与漏点位置相关。文中方法综合利用地质、工程、地质力学数据,可为新探区提供可靠的漏失压力精细预测结果,有助于新探区的钻井优化设计和管理。

To address the serious lack of geological and engineering data of fractured formation in the new exploration area which reduces the effectiveness of the existing calculation model of leakage pressure,this paper provided a geology-engineering integrated prediction method for leakage pressure in fractured formation.Based on the existing calculation model of leakage pressure,this method introduced the fracture indexes,combined with the mud leakage mechanism,formulated the classified evaluation indexes of leakage types,and formed a three-dimensional modeling method for leakage pressure in fractured formation.Moreover,the classified evaluation indexes of leakage type of Bohai Sea oilfield A were established,and three-dimensional leakage pressure modeling and predication of oilfield A was carried out,which was successfully applied to Well C-5,and the drilling cycle was shortened by 15 days.The application results showed that the fracture index of oilfield A was directly related to the location of the leak point.The method in this paper comprehensively utilizes geological,engineering and geomechanical data,which can provide reliable fine prediction results of leakage pressure for new exploration areas,and is conducive to optimizing the drilling design and management in new exploration areas.