Single Well Tests to determine the Efficiency of Alkaline-Surfactant Injection in a highly Oil-Wet Limestone Reservoir

Abstract

TX 75083-3836, U.S.A., fax 01-972-952-9435. AbstractThe Mauddud carbonate reservoir is the main oil producer in Bahrain oilfield that has been undergoing crestal gas injection with natural aquifer support at the flanks. It has been producing since 1932 and currently in a very mature stage. Due to its rocks wettability characteristics (preferentially oilwet nature), the residual oil left behind gas and water fronts range from 20-70%. One of the potential options to recover portion of this residual oil is through Chemical Flooding possibly Alkaline-Surfactant-Polymer (ASP) flood. A project was hence initiated to investigate its technical and economical feasibility. It was decided to carry out field experiments to gauge the reservoir response through well-bore treatments before proceeding with a full-scale study and field pilot implementation. Initial field-testing on single-well huff-andpuff basis with experimental recipes provides sufficient positive indications for the project to proceed.The results of these initial tests are presented in this paper.

Review of surfactant-assisted chemical enhanced oil recovery for carbonate reservoirs: challenges and future perspectives

“…Lack of adequate practical knowledge about surfactants used in dual-porosity fractured carbonate reservoirs, limits their performance to a great extent (Manrique et al 2007). In a few cases reported for surfactant-based cEOR for carbonate reservoirs, which include the Mauddud carbonate reservoir of Bahrain (Zubari and Sivakumar 2003), Yates field in Texas (Yang and Wadleigh 2000), Cottonwood Creek field in Wyoming (Xie et al 2004) and the Baturaja Formation in the Semoga field of Indonesia (Rilian et al 2008), the temperature was about 45°C and never higher. Therefore, much work remains to be accomplished for HTHS carbonate oil reserves to establish credible production baselines and successfully capture the recovered mobilized oil (Kiani et al 2011).…”

Enhanced Oil Recovery: An Update Review

“…However, ASP has been tested in carbonate formations in the lab in Arab-D [193] and Upper Edward's [19] and Pietra Leccese outcrop [194][195][196] in core samples. Alkali-Surfactant single well test has been reported in the Mauddud carbonate reservoir in Bahrain as part of ASP feasibility studies in oil-wet limestone reservoirs [197].…”

Chemical Flooding in Naturally Fractured Reservoirs: Fundamental Aspects and Field-Scale Practices

“…In the following paragraphs, the pilot/field projects of the chemical flooding in the Mauddud Reservoir (Bahrain), Stone Bluff Field (Oklahoma), Townsend Newcastle Sand Unit (Wyoming), Big Horn Basin (Wyoming), and North Burbank Unit Block (Oklahoma) are reviewed. Zubari and Sivakumar (2003) reported the results of several single-well tests to determine the efficiency of AlkalineSurfactant (AS) injection in Mauddud carbonate reservoir, which is a highly oil-wet heterogeneous limestone reservoir with fractures and vugs. Production from Mauddud was started in 1932.…”