Abstract
The use of progressive cavity pumps (PCP) in the offshore assets (Soldado Field) of the Petroleum Company of Trinidad and Tobago Limited (Petrotrin) began with pilot projects in early 2000, however full adoption of this artificial lift system occurred from 2003-2005. Almost a decade after and due to a reduction of run life of the pumps and the increase in workover frequency, a complete review of the PCP system was done in order to identify type and causes of failures, present best practice solutions to reduce premature failures and recommendations for optimum design and operation. This paper discusses the results of the review and the steps being implemented by Petrotrin Trinmar Operations towards the management of PCP during the productive life of an oilfield.
The initial approach was the visit of Subject Matter Experts (SME) to Petrotrin Trinmar Operations to consult with production engineers and field operators on the problems experienced. Detailed evaluations were performed on the type of failures and their location in the PCP system. Destructive and non-destructive test were done on selected rods, pumps and accessories. Supervision during the running of sucker rods into producing wells to ensure the proper installation of the systems. Revision of the processes and participants in the management of Artificial Lift Systems (ALS) i.e. identification of candidates wells for PCP, design and procurement of these systems, installation and pulling, monitoring and maintenance. The process was completed with the establishment of Key Performance Indicators (KPI) to assist in decision making regarding the performance of PCP.
The results indicated that the run lives of most PCP systems in Petrotrin Trinmar Operations were similar and sometimes above the average of systems installed in North America. The common failures were categorized as mechanical due to wear and tear during operations, lack of maintenance and improper design. Some of the reasons for early failure were attributed to improper manufacturing and installation of new systems. Delegation to the suppliers of the design, selection and installation of PCP was a good approach during the learning curve of operators (Petrotrin Trinmar Personnel), however as the systems were fully adopted by the company, appropriate training and development of a culture associated to the use of PCP needed to be developed since these classic systems can turn into new technologies due to their scarce use.
PCP Management should be taken as an integrated vision in accordance with the development of the Soldado field due to the need to maximize production and the high economic impact that the products and services associated to PCP have on lifting costs.
