苏北凹陷北汉庄油田出砂机理研究及防砂工艺优选

RESEARCH ON SANDING MECHANISM IN BEIHANZHUANG OILFIELD IN SUBEI SAG AND OPTIMISING OF SAND CONTROL TECHNIQUE

苏北溱潼凹陷北汉庄油田主要出砂原因为油层胶结疏松、地层压力下降、强水敏、原油粘度高、含水上升等。该油田油井出砂指数都小于2×104MPa,声波时差均大于295μs/m,平均孔隙度为37%,这三个方面的预测结果均表明出砂不可避免,因此,必须采取相应的防砂措施。针对该油田特点优选了封隔高压一次充填防砂工艺作为主要的防砂工艺,在三口油井中实施后含砂量大幅下降,而产量和含水率变化极小,取得了明显的效果。

The analysis results of sanding in Beihanzhuang Oilfield of Subei Sag show that the main causes are unconsolidated oil layer, dropped formation pressure, strong water sensitivity, high crude viscosity, risen water cut, and so on. The sanding index of oil wells in the field are all lower than 2×104 MPa, the sonic differential time of them are all higher than 295 us/m, and the average porosity is 37%. All the three forecast results show that sanding is unavoidable, and the corresponding sand control measures must be taken. In consideration of the characteristics of the oilfield, the one-pass high pressure filling technique with packing the higher and lower formations is selected as the main sand control measure. After application in three oil wells in the field, the sand content dropped greatly, meanwhile, and the output and the water cut only had a little change. So a good sand control result has been achieved.