蛇曲井生产井段压降预测方法

蛇曲井是一种新型复杂结构井,生产井段存在较大的纵向起伏,井筒流动特征既不同于普通水平管,也不同于水平井.研究了蛇曲井井筒流动特征,对蛇曲井微元段和孔眼段的流动进行了分析,根据质量守恒原理和动量定理,建立了裸眼完井和射孔完井方式下蛇曲井生产井段的井筒压降预测模型.在定产量和定井底流压两种工作制度下,给出了蛇曲井生产井段的压降预测方法.应用所建预测模型和水平井的水平段压降计算模型分别计算了某裸眼完井蛇曲井生产井段的井筒压降,结果表明:蛇曲井生产井段井筒压降不能用常规水平井水平段的压降模型计算,蛇曲井生产井段井筒压降不能忽略.

PREDICTION METHOD OF THE PRESSURE FALL IN PRODUCING WELL SECTION OF SNAKY WELL

Snaky well is a new type of complex well. Its producing well section is rugged longitudinally. The flow property of Snaky wellbore is different from horizontal pipe and horizontal well's. The article researched the flow property of Snaky wellbore and analyzed the flow for the mini-element section and perforation section of the snaky well. Based on the continuity equation and the momentum equation, the pressure fall models of wellbore flow within an open-hole and a perforated completion snaky well bore are established .The calculating methods of pressure fall were proposed for producing well section of the snaky well under the two working systems of constant production and constant bottom-hole pressure. The pressure fall of the producing well section of an open-hole completion snaky wellbore was calculated separately using the model established in the article and the calculating model of pressure fall for the horizontal section of the horizontal well .The results showed the pressure fall of the producing well section of snaky well couldn't be calculated with the pressure fall model of the horizontal sections of conventional horizontal wells. The pressure fall of producing well section of snaky well couldn't be omitted.