The Harweel Cluster in Southern Oman is PDO’s first EOR Project. It is being developed in a phased manner using miscible gas injection. Reservoir simulations have been carried out to show that a significant increase in ultimate recovery can be achieved by successfully isolating gas (and water) if it breaks through prematurely to producing wells. In order for the additional reserves to be obtained, zonal isolation is required over the reservoir section. To date, isolation has proved to be inadequate using conventional cementing technology and techniques.

A trial was therefore carried out to determine the effectiveness of using oil swellable elastomers ("Swell Packers") to achieve zonal isolation. Three swell packers were run in a well and tests were devised to determine the success of the elastomers following expansion.

Based on the results, zonal isolation was achieved as indicated by a combination of selective perforating, wireline logging and production testing. This is the first time that zonal isolation has been observed in these challenging, HP, sour wells.

You can access this article if you purchase or spend a download.