Ensuring a pilot project a success operationally, while gathering reliable data for a full-field implementation is critical. For this reason, various aspects of project planning and operational considerations need to be addressed. This include conceptual design, facilities and operational considerations, resources planning, integration of activities and most importantly, pilot objectives. However, all these planning will not be successful without a properly designed and executed laboratory test program. Such laboratory program will minimize result uncertainty and ensure the proposed pilot meet its objectives. The first Chemical EOR (CEOR) pilot project in Malaysia involved an Alkaline-Surfactant injection utilizing high salinity injection water in a high temperature reservoir. It pioneered the Single Well Chemical Tracer (SWCT) method for EOR project evaluation in Malaysia. The main objective of the pilot is to assess the effectiveness of the Alkaline-Surfactant formulation to improve oil ultimate recovery through the reduction of residual oil saturation. Being the first of its kind in Malaysia, an extensive laboratory program is required to ensure the injected alkaline surfactant formulation performed at its most optimum and conclusive data is gathered. This data will be used as input to the future field development plan. This paper presents a comprehensive laboratory test program covering pre-pilot, pilot and post-pilot laboratory analysis designed for offshore high salinity injection water and high temperature reservoir. It highlights the challenges imposed by offshore operation to design an optimum chemical solution considering that salinity and hardness of the water used to dissolve the chemicals are critical for an alkaline-surfactant system. It also discusses the continuous and controlled quality check process to validate the performance of the alkaline-surfactant solution. Finally, it presents the chemical adsorption study to evaluate chemical flood potential for the future full field CEOR implementation. Introduction PETRONAS has undertaken a 3-year R&D project which evaluated the feasibility of a CEOR process for Malaysian oilfields. The research also identified suitable chemicals that can withstand the high temperature and high salinity environment and suitable candidate reservoir for pilot implementation (Othman et al. 2007). Based on the R&D study, Angsi field, located east coast of Peninsular Malaysia was selected for pilot implementation. The execution of this pilot project was also targeted to establish the required technical, operational and management skills before embarking on a large scale full field chemical flood. The results of the CEOR pilot project are crucial to the future decision making for full field implementation. A lot of considerations were given to gather reliable and conclusive data, within which, will manage results uncertainty. One of the ways is to ensure accuracy of the chemical preparation and injection process. All these can be achieved by a properly designed laboratory test program to tackle specific issues on optimum chemical slug design and quality of chemicals injected. It also aimed to measure the degree of chemical loss to reservoir rock, in which will evaluate the sustainability of the chemicals in a high temperature reservoir.

Angsi field is located offshore Terengganu, Malaysia. It was identified as the candidate for a pilot project to evaluate the effectiveness of chemical enhanced oil recovery (CEOR). Injection of alkali-surfactant (AS) slug was used to improve recovery factor through the reduction of residual oil saturation (Sor). The pilot project utilized single well chemical tracer test technique (SWCTT) to measure Sor change near well bore due to reactions of CEOR process. The pilot results were later used to update the reservoir dynamic model and to support decision making for potential expanded field application. The pilot project faced many challenging technical and operational obstacles: offshore location, high reservoir temperature, sea water as injection water, water softening facilities requirement, and unmanned satellite platform with limited space. In addition, compliance to all Health, Safety, and Environment (HSE) requirements is a must, to ensure the pilot operation is carried out in a safe manner. This paper will focus on the overall pilot design, planning and some results. Operational, HSE and quality control will also be discussed as background to the pilot project.

The Angsi field in the offshore Terengganu, Malaysia was identified as the candidate for the pilot project to evaluate the effectiveness of the Alkaline Surfactant (AS) process in improving oil ultimate recovery through the reduction of residual oil saturation. The pilot project entails the injection of AS chemical into Angsi I-68 reservoir and will use a Single Well Tracer Test (SWCT) to determine the residual oil saturation in water-flooded area. This is the first chemical Enhanced Oil Recovery (EOR) pilot project in Malaysia and the results are crucial to support the decision making for a future full field and AS technology implementation in Malaysia. High reservoir temperature and high water salinity pushes the technical limit of AS application that adds complexity to the pilot design. The implementation of the pilot project in the offshore environment, on an unmanned satellite platform with limited space and facilities provide additional operational challenges to the project team. In addition, the utilization of new and volatile chemicals during the pilot requires an introduction of various field procedures to ensure the operation is carried out in a safe manner. The paper showcases, the key challenges in the planning and execution of the first offshore AS pilot project in the region. This challenging task demands the multi-disciplinary team to work together to develop the project execution plan with attention to detail during pilot design, planning and operation. As a result, critical parameters such as: treatment sequence, field procedures, equipment requirements and layout, and logistics were considered. The pilot design and procedures that are crucial for a successful pilot operation were developed within the constraints imposed by the offshore environment. Introduction In their quest to increase oil ultimate recovery and extend field life, PETRONAS spearheaded various Enhanced Oil Recovery (EOR) initiatives in Malaysia. The Chemical Enhanced Oil Recovery (CEOR) was identified as one of the EOR process that has good potential for the field implementation to increase ultimate recovery in Malaysian oil fields. Consequently, a research project was carried out to evaluate various CEOR processes and to identify candidate reservoir for a possible pilot implementation. The encouraging result (14.6% OOIP incremental recovery) for alkaline-surfactant (AS) process has proved that there is potential for CEOR application at Malaysian oil fields despite the harsh environment (high temperature and high salinity) for CEOR process1. The research has successfully identified suitable chemicals that can withstand the harsh environment and a suitable candidate reservoir for pilot implementation. The research works also included the design of AS formulation tailored to the test reservoir. Subsequently, the CEOR pilot project was proposed and implemented at Angsi I-68 reservoir to evaluate the effectiveness of the AS process at reservoir condition in improving oil ultimate recovery through the reduction of residual oil saturation, Sor. The AS technology combines synergistically, the interfacial tension reducing effect of added surfactants and those produced in the acidic crude oil by alkaline reaction of organic acids. AS flooding shows promise of being cost-effective because alkali, in addition to reinforcing the activity of surfactants, reduces the depletion of surfactant that occurs due to adsorption/retention in the reservoir 2–3 . The Angsi CEOR pilot project marked a significant milestone for the Malaysian oil and gas industry as it was the first CEOR project implementation in the country. The results of this pilot project are crucial in the future decision making for a large-scale full field and AS technology implementation with reduced technical risk. The result may be one of the keys in deciding the fate of the CEOR implementation in the Malaysian oilfields. In implementing this pilot project, together the team tackled and overcame significant technical and operational challenges.