Gas Well De-Watering System and Hydraulic Gas Pump, New Designs and a Discussion on Their Economics

Abstract

SPE Member Abstract The concepts for two new artificial lift systems were first presented in SPE paper 25422. In the present paper improved designs are presented. The application and the economics of the Hydraulic Gas Pump are compared to the gas lift method that was used in East Quito Fusselman Reservoir, Ward County, Texas. The author concludes that the Hydraulic Gas Pump can be a more economic artificial lift method than gas lift for East Quito Fusselman Reservoir. Introduction The problem of liquid loading in gas wells is due to the hydrostatic weight of the liquids that are entrained in the gas flow. This weight exerts a back pressure on the formation that acts like a choke reducing the flow rate. When the back pressure exceeds the flowing bottomhole pressure of the well, the well stops producing. At this time some form of artificial lift is required to continuously or intermittently remove liquids from the gas well. For many wells a high pressure drawdown on the formation is necessary in order for the well to produce at economic rates. Methods such as gas lift, plunger lift or velocity string exert a back pressure on the formation and in many cases can not produce a well to its full potential. These methods become even more limiting for deeper wells. Among different methods of artificial lift that are currently used for de-watering gas wells, a pump is the only method that offers the important ability of providing high drawdown on the formation However the existing pumps such as rod pump, ESP, progressive cavity, jet and hydraulic pump have problems operating in wells that produce large volumes of gas. The Hydraulic Gas Pump and the Gas Well De-watering System are designed to operate in deep and gassy environments. Therefore, these systems have the potential of being useful artificial lift devices that can produce certain hydrocarbon reservoirs at a higher production rate and to a lower abandonment pressure than the existing artificial lift methods. Designs The Hydraulic Gas Pump (Fig. 1) and the Gas Well De-watering System (Fig. 2 and 3) are two proposed methods for pumping oil wells or for dewatering gas wells. The two systems are similar in operation. P. 67^