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The BDO EOR feasibility study conducted in 2004 by PETRONAS and Sarawak Shell Berhad (SSB) identified a potential incremental recovery of over 250 MMstb from the Baram Delta Operation (BDO) fields1. This incremental oil can be realized from CO2 injection under miscible and immiscible conditions. On average, this represents an additional 12% incremental recovery above the base case of water flooding. The regional CO2 injection covering nine (9) fields requires a very significant investment of new CO2 infrastructures and injection facilities. To mitigate the risk involved and to prove the commercial viability of the project, a regional pilot was proposed. The pilot, which will be implemented in Baronia RV2 reservoirs, will serve as a basis to formulate the way forward for CO2 injection in the whole BDO region. Several extensive evaluations were carried out to come up with an optimized pilot design. This includes building full field compositional fluid flow simulation model for CO2 miscible flood predictions and sensitivities, streamlines analysis to identify suitable well pairing, and MMP / interfacial tension measurements in the laboratory. The proposed observation pilot were specifically designed to address several issues such as determination of current oil saturation, waterflood residual oil saturation, residual oil saturation after gas flooding and evaluation of the vertical sweep efficiency. The pilot will also serve as an opportunity to acquire additional data through extensive coring, logging, and fluid sampling programs. This paper outlines the methodology used in the developing the most cost-effective pilot at Baronia RV2 reservoirs that could potentially lead to economic maturation of new reserves in the whole of the BDO area as well as formulating the most comprehensive monitoring and evaluation techniques of the pilot. Introduction The Baram Delta area which is located at offshore Miri of Sarawak consists of nine (9) fields as shown in Figure 1. The area which was discovered in 1969 is estimated to have more than 4000+ MMstb oil in place with multiple stacked sandstone reservoirs in a shallow offshore environment. They have been on production for more than 30 years and the historical production data indicated that the oil production have been relatively flat at 80 - 100 kbd of oil primarily from infill drilling and new in-field development and/or rejuvenation. Figure 2 shows historical production performance of the BDO area. Currently, many wells are shut in due to the high water production. Because of offshore environment, well spacing is relatively large and limited available space at the platform which make these characteristics present a challenging environment to carry out EOR operations. The stratagraphic framework for Baram Delta reservoirs is mainly from Middle Miocene in age with east-west oriented coastline and a delta progradation southeast to northwest as shown in Figures 3 and 4. The principal reservoirs are cycle V/VI regressive coastal plan and fluvio-marine sandstones2. The depositional environments observed vary where shoreface deposits exhibit higher connectivity and higher areal sweep. The multiple stacked pays in multiple fields means that there are most probably many thief zones in the area reflected by a low recovery factor of around 29% only. Looking at this issue positively, it can be inferred that BDO area still has a lot of future oil potential through EOR applications.

fax 01-972-952-9435. AbstractThe BDO EOR feasibility study conducted in 2004 by PETRONAS and Sarawak Shell Berhad (SSB) identified a potential incremental recovery of over 250 MMstb from the Baram Delta Operation (BDO) fields 1 . This incremental oil can be realized from CO 2 injection under miscible and immiscible conditions. On average, this represents an additional 12% incremental recovery above the base case of water flooding. This paper outlines the methodology used in the developing the most cost-effective pilot at Baronia RV2 reservoirs that could potentially lead to economic maturation of new reserves in the whole of the BDO area as well as formulating the most comprehensive monitoring and evaluation techniques of the pilot.

This paper is an update to an earlier submission[1] and presents the current status and progress of several main EOR projects in Malaysia. As of January 2005, the estimated oil-in-place from producing fields in Malaysia stands at about 17.0 Bstb[2], with estimated ultimate recovery (EUR) of 5.62 Bstb. This translates to an averaged recovery factor of only 33.0 percent for producing fields in Malaysia. PETRONAS had realized the importance to further increase the recovery factor and so far has been pursuing EOR implementation in its fields aggressively. To date, a full-field WAG application in Dulang field[3,4] is already at its final stages of implementation. In addition, EOR projects have also been planned for another ten fields i.e. Tabu, Tapis, Guntong, Tiong/Kepong and Angsi in Peninsular Malaysia and Baronia, West Lutong, St. Joseph, Bokor and Baram in East Malaysia. Each of the project is currently at different level of maturity and some preliminary results for five selected EOR projects that are in the late stages of study or in the pilot phase; namely in Dulang[3,4], Tabu, Baronia, West Lutong5 and Tapis6 fields will be discussed in this paper. Introduction Malaysia oil reserves were in declining trend starting from 1994 to 2002 (Figure 1) but reversed its trend with the discoveries of deepwater fields. In 2004, Malaysia's average oil production was about 620 thousand barrels per day. With no new reserves addition, Malaysia would quickly deplete its reserves and at current rate of production, the expected reserves life is only about 19 years. With responsibility of developing and adding value to these resources, PETRONAS, short for Petroliam Nasional Berhad, was established in 1974, has the responsibility of developing and adding value to these key national resources. The corporation is vested with the entire oil and gas resources in Malaysia and is engaged in a wide range of activities, including upstream exploration and production to downstream of oil refining, petrochemicals, retail business, marketing, trading, gas processing and liquefaction as well as in logistic and maritime. Through various efforts undertaken by PETRONAS, the reserves have returned to an upward trend, and as at January 2005, the Malaysian oil reserves stood at 4.1 billion barrels2. In a matured exploration and producing area like Malaysia, one of the ways to increase oil recovery is through implementation of EOR projects. In view of this, PETRONAS had conducted a screening study in year 2000 to identify EOR potential in Malaysian oil reservoirs7. The outcome of the study indicated that an estimated un-risked incremental recovery from EOR is about 1 Bstb. It is also interesting to note that the year 2000 study identified CO2 miscible process as potential EOR in 4 out of the top 6 candidate reservoirs (Figure 2). EOR Initiatives Recognizing the potential of enhanced oil recovery in the fields, the national oil company endorsed a comprehensive IOR/EOR screening study in year 20007.The main processes studied were chemical, gas flooding and microbial enhanced oil recovery, processes that were considered having the most practical aspects in the Malaysian oil fields.The hydrocarbon and CO2 gas flooding in miscible or immiscible mode were found to be the most favorable processes, although the applications for miscible processes are limited due to depleted reservoir pressures.To further enhance sweep efficiency, mobility control (such as in WAG) and optimizing operating cost for the injectant seems to be the way forward.Most of the proposed gas flooding will be implemented together with water injection in water-alternating-gas (WAG) scheme.