Effective Well Integrity Management in a Mature Sour Oil Field

Maximizing the productive life of wells and minimizing the risk of uncontrolled release of reservoir fluid over the entire life cycle of the wells are the major objectives of any E&P company. Therefore, managing well integrity has become as important as managing reservoirs without compromising the safety of personnel or the harmony of the environment, and at the same time protecting valuable assets for a prolonged life. One of the large mature onshore oil fields of Saudi Arabia is producing sour crude oil that multiplies the well integrity challenges. A stringent well integrity surveillance and maintenance program is followed for this field to ensure the integrity of every individual well. The program, essentially developed for Saudi Aramco onshore oil fields, is a proactive problem prevention-based approach. Under this program, any well integrity related problem can be predicted through a structured preventive diagnosis and maintenance schedule for both wellhead and downhole integrity to assure well integrity that verifies and confirms the status of wells with suspect integrity. The program is governed by the operating standards and guidelines for maintaining the well integrity parameters, ensuring safe well operations and securing uninterrupted well productivity and injectivity. The program also emphasizes the requirement of barriers during normal operations, unscheduled well interventions or when shut-in for safety and environment protection. This paper describes the process for efficiently managing well integrity throughout the development life cycle with a particular focus on production operations and the well maintenance phase. The objective of this paper is to provide an overview of the rationale for following this structured program and the realized benefits.