气举—泡排组合工艺井底压力计算及施工参数优化设计

Calculation of downhole pressure and optimization design of construction parameters for gas lift and foam combined technology

基于气举—泡排组合工艺井井筒中的混合流体是由泡沫(或泡沫团)与泡沫外气体组成并相互滑脱这一模型,引入持泡率这一参数,相继推导了确定泡沫密度、持泡率和混合流体密度等主要参数的计算公式,从而可以确定井筒压力剖面并计算井底流压。通过实例计算与对比,验证了计算方法的可行性,为气举—泡排组合工艺的施工参数的优化设计提供指导。气举—泡排组合工艺的井筒压力剖面计算方法,只需借助于计算机程序,节约了复杂的测压作业,提高了经济效益。

In view of the model that the mixtures in the wellbore implementing gas lift and foam drainage combined technology is composed of foam and free gas out of foam which get off from each other, this paper introduced the parameter ＂foam retention rate＂ and then derived a series of formulas to calculate the density of foam, ＂foam retention rate＂ and the density of wellbore mixtures, so as to determine wellbore pressure profile and calculate bottom hole pressure. This paper also verified the feasibility of the calcula- tion method by the calculation examples and results comparison to provide guidance for the optimization design of implementation parameters. The calculation method only has to calculate with a computer grogram to solve the complex work of pressure testing and irnnrav~ th~ t^conamic~.