Innovative Annulus Pressure Monitoring and Control Design for High Pressure Class I Wells with Depths in Excess of 10,000 Feet

January 22, 2018

High pressure injection of liquids can be challenging in Class I wells where depths exceed 10,000 feet and extreme temperature variations occur between injection and shut in conditions. Elevated downhole temperatures at these depths create a high temperature differential between the injectate and annular fluid resulting in significant swings of annulus pressure and surface seal pot volumes. One-way micro tubing leaks at joints have also occurred due to these conditions.

The injectate cools the annular fluid resulting in contraction of the annular liquid and lowering of the seal pot volume, which requires addition of fluid into the annulus. Once the wells are shut in, annular pressures rise as the annulus fluid is warmed by the native formation fluid, creating an increased pressure differential on the downhole components and increasing the seal pot volume and potentially creating high pressure situations in the annulus. In addition to the labor-intensive operation of having to add and remove liquid from the annular space, greater downhole pressure differentials may affect long-term integrity of the injection tubing and protective casing.

Maintenance of an annulus pressure that is less than the injection pressure, similar to the operation of more shallow Class I wells, is impractical under the operating scenario for deeper wells. It also creates the potential for fluid migration from the tubing into the annular space in the event of a leak.

Monte Markley, P.G., and Stephanie Hill  will present this and more at the 2018 Underground Injection Control (UIC) Conference. The presentation will focus on the design and implementation of an innovative high pressure annulus monitoring system that mitigates the presence of micro tubing leaks in joints, and pressure and temperature swings of the annulus.

Learn more about DIW here.

Posted by Diane Samuels at 6:01 am
SCS Address

Corporate Headquarters

3900 Kilroy Airport Way Ste 100
Long Beach, CA 90806-6816

Telephone

1 (800) 767-4727
1 (562) 427-0805 | FAX
service@scsengineers.com

Subscribe To Our Resources

Sign up to receive periodic bulletins of environmental issues of interest such as: regulatory policy, court cases, tax incentives, emission standards, and more.

By signing up you agree to the terms and conditions outlined in our Privacy Policy.