At Esso Resources Canada Ltd., we have been using electric submersible pumps in our operations since the early 1960's. Currently. we have approximately 250 pumps in operation.
In the past, submersibles proved to be an efficient, economical means of lifting high volumes of production despite high operating costs. With declining reservoirs and increasing water production, the operating costs of submersibles have become more critical and run-life has become the key to economic viability.
Submersible pumps are unforgiving to any kind of carelessness or abuse during manufacturing, shipping or installation. Failure modes are few, and are easily identified but failure causes are many, and often go unrecognized. To improve submersible pump run-life, these causes must be determined, and ways to prevent them must be developed and implemented. Over the past two years, we have put considerable effort into improving submersible pump run life at our Redwater and Judy Creek fields. This paper describes some of the areas where we have implemented changes in our submersible operations. Among the areas discussed are: failure monitoring, cables and splices. potheads, and corrosion inhibition. S1nce identify1.ng and implementing improvements. we have begun to see a gradual increase in pump run life and a reduction in our operating costs. In Redwater, where well characteristics are mild (low gas. cool. shallow), we believe a run life of 5 years is achievable. In Judy Greek, where conditions are more severe, (warm, deep, high gas, tight clearances). we believe a run life of 2 years is achievable. With these goals. we are continuing to search for, and develop, methods to improve submersible pump performance.
Since the late sixties, electric submersible pumps have played a large part in oil recovery strategy in Canada. At Esso Resources, we currently operate about 250 submersible pumps. primarily in our Redwater and Judy Creek fields. Where artificial lift is required. submersible pumps have provided a low capital cost method of lifting large volumes of production. Their major drawback has been high operating costs due to short run lives. Submersible operating costs were barely tolerable in the late seventies when the economy was experiencing rapid growth. With the present economic situation reducing operating costs has become critical and major efforts are being expanded to find methods to reduce these costs. Our philosophy has been that by increasing the life of individual submersible components, we can expect to increase the operating life of the whole system.
This paper will discuss several ways of increasing submersible pump run life by examining individual pump components. The areas that will be discussed are: failure monitoring, cable system design, pothead design, pump design and corrosion.
Keeping detailed, accurate records, including both operating history and failure information, is the first step toward improved submersible pump system life. This information can then be used to monitor failure trends and to determine what the failure causes are. Treating effects, and trial and error methods for improving run life, will be eliminated.