Abstract
Globally, many thousands of potentially productive oil and gas wells suffer internal corrosion due to H2S, CO2, and other produced gases and liquids. This limits their capability to provide a packer sealing area suitable for traditional mechanical production packers. Total E&P Qatar planned a recompletion using intelligent well technology in a well in which they expected to find some corrosion. Before initiating the recompletion, they investigated the use of alternative packer technology.
Swelling elastomer packers have been used worldwide in many applications, but verification was required in this case to assess whether such packers would hold pressure in a corroded section of casing. In addition, testing was also was needed to assess whether the completion could be pulled in the event that it became necessary to retrieve the components from the well.
A swellable packer with multiple cable feed-through was designed and manufactured to approximately two-thirds size of the originally specified packer. A sample of corroded casing, supplied by Total E&P Qatar, was used to build a test jig. The jig was equipped to simulate and record pressure, temperature, and other downhole conditions. Theoretical simulations were performed to assess the force required to overcome the anchoring forces applied by the swelled elastomer and were verified by a pull test.
It is expected that with a reliable sealing mechanism for these older wells, technically and financially viable workovers and re-completions can be performed, thereby extending field life and adding to recoverable reserves.
This paper describes the application and test procedures along with the verification and results of the testing performed.
