DefinePK

Abstract

In the petroleum literature, non-Darcy flow is assumed to be a near wellbore phenomenon; consequently a gas reservoir could be divided into Darcy’s flow domain and non-Darcy’s flow domain. Assume only radial flow occurs in the near wellbore non-Darcy’s flow domain, and assume the radius of this domain is integer multiple of wellbore radius, Lu et al. (2011) proposed binomial deliverability equations for partially penetrating vertical gas wells and horizontal gas wells. By solving a set of simultaneous equations with respect to non-Darcy’s flow domain rn and flow rate at standard conditions Qsc, this paper presents new binomial deliverability equations for horizontal gas wells, which can account for the advantages of horizontal gas wells where non-Darcy effect is less pronounced than that in vertical gas wells. The calculation results show that non-Darcy flow domain radius is smaller than 15 times wellbore radius, which further proves turbulent effect only occurs in the vicinity of wellbore. The calculation results also show that the production rate loss of horizontal wells caused by the turbulent flow is small.