Proactive Surveillance Creates Value in Well and Reservoir Management

Abstract

This article, written by Senior Technology Editor Dennis Denney, contains highlights of paper IPTC 13646, ’Creating Value in Well and Reservoir Management Through Proactive Surveillance,’ by Ahmed Al-Azkawi, SPE, Mohamed Al-Salhi, SPE, Liping Sha, SPE, Ramzi Abdulkadir, SPE, and Hamed Al-Subhi, SPE, Petroleum Development Oman, prepared for the 2009 International Petroleum Technology Conference, Doha, Qatar, 7-9 December. The paper has not been peer reviewed. Proactive surveillance adds value to fields that follow a clear well- and reservoir-management (WRM) strategy. Sustainability of these processes requires surveillance plans applicable to each scenario and stage of the field’s life. This proactive approach to surveillance yields frequent insight into the reservoir condition and proves valuable in mitigating unpleasant surprises. Introduction In the late 1990s, Petroleum Development Oman (PDO) was challenged by its mature fields experiencing faster decline rates and new wells contributing lower production. The company identified key business processes to reverse the production-decline trend. One process was WRM. Daily focus on WRM has reduced the overall PDO production-decline rates significantly. The full-length paper details how WRM is practiced in one of PDO’s clusters of fields and how it helped increase production. The cluster is in southern Oman and comprises 23 small fields. Production is from a sandstone reservoir at depths ranging from 900 to 2500 m, with oil gravity varying between 20 and 50°API. The cluster has fields undergoing waterflood development and fields in depletion mode (i.e., aquifer support is sufficient to maintain reservoir pressure). WRM Process Approximately 239 hoist interventions are carried out each year in the cluster, and a significant amount of resources and budget is spent on standalone optimization and surveillance activities. The WRM process enabled execution of these activities more efficiently and helped to improve the recovery factor and production. The focus of the WRM process was to: Increase reservoir understanding Optimize field-development plans Improve the placement of new wells Safeguard developed reserves The preplanned well and pattern review ensured proactive surveillance. The purpose of proactive surveillance was to understand current field behavior, optimize production, and add new reserves. This process of gathering data before a problem occurs coupled with preplanned review contributed greatly to the production and the recovery factor of the cluster. The next challenge was to embed this process into a cluster of 23 fields and to sustain it. Given the variety of drive mechanisms, maturity, and properties among these fields, it was important to define WRM for each field. The process was embedded and monitored by generating key business activities and key performance indicators that targeted: The number of field/well/pattern reviews Compliance with surveillance plans Compliance with workover plans Well potential identified during the reviews Oil recovery identified during the reviews