Slim Hole Artificial Lift

Jim Lea, PL Tech Bennie Williams, Harbison-Fischer

Abstract

Many wells, including many gas wells, have been completed with 2 3/8's, 2 7/8's, or 3 1/2 inch casing sizes to reduce drilling and completion costs. When the wells must be pumped, such as when de-watering gas wells, clearances become a problem. There are many instances where it is necessary to install a beam pump in a slim-hole completion for lifting fluids from liquid loaded gas wells.

Casing pump & hollow rod completions. For slim-hole applications with beam pump, there are two possibilities. One is to simply land the pump with an insert anchor inside small casing (as small as 2 3/8’s or 2 7/8’s inch) and produce the fluid though the pump with a casing pump. This application will not work for a gas well but could for an oil/water well with little gas.

The other possibility is to use a tubing insert anchor with the rubbers stripped out of the anchor and let gas bypass the pump. In this situation, gas bypasses the pump while fluid is produced from the hollow rods. Hollow rods and also coiled tubing for rods are possibilities to allow gas venting.

Small tubing inside small casing. Another possibility, which allows gas venting, is to use very small tubing within a 2 7/8 inch completion. A small string of rods is run inside the small tubing.

These and other slim-hole beam applications are presented with their limitations. Also an overview of hydraulic, PCP, and gas-lift slim-hole applications is overviewed.