Revitalisation of South Fawares Field Using Open Hole Multistage Completion Systems – A Pilot Project Case Study

Abstract

Abstract Located in the Partitioned Neutral Zone between Kuwait and Saudi Arabia, the South Fawares field has been producing from the Lower Cretaceous Ratawi reservoir since 1956. Several conventional coiled tubing acidizing treatments have been performed to restore productivity from the Ratawi formation. However, due to the formation heterogeneity, limited zonal coverage and inconsistent acid distribution, these treatments resulted in limited improvements to productivity. The objective of this study was to determine the most appropriate re-completion/stimulation technology that could achieve the following: Effectively and evenly stimulate the entire horizontal section,Benefit from the vast network of natural fractures within the formation matrix to further enhance production, andMaintain wellbore integrity. This paper presents a successful pilot project implementing horizontal open hole multistage completion systems for the first time in the South Fawares field. Existing lateral sections drilled across the Ratawi formation in the South Fawares field were segmented into several stages and each stage was fracture acidized separately to achieve optimum acid placement and maximize the net stimulated reservoir volume. The results show that effective wellbore isolation between stages coupled with efficient diversion of the stimulation fluid is key to improved well productivity. This paper highlights the planning, execution and challenges of the installation of these systems with comparisons of pre- and post-stimulation data and offset wells. The success achieved from the first deployment of open hole multistage completion systems in the South Fawares field has opened new opportunities for reviving the productivity of additional depleted wells. Introduction The South Fawares field is situated in the Partitioned Neutral Zone (PNZ) between Kuwait and Saudi Arabia, (Fig. 1), where the natural assets are shared jointly under the Neutral Zone agreement signed in 1922. Since 1949, Saudi Arabian Chevron, a 100% owned subsidiary of Chevron, the Kuwait Gulf Oil Company and their predecessor companies have operated four oil fields in the onshore PNZ. The fields are Humma, South Fawares, South Umm Gudair and Wafra. In 2009, the 60-year agreement between Saudi Arabia and Chevron predecessor, Getty Oil Company was amended and extended for another 30 years. Under this agreement, Chevron operates Saudi Arabia's 50 percent interest and the Kuwait Gulf Oil Company operates Kuwait's 50 percent interest in the PNZ.