This paper is a review of offshore oil fields development in Malaysia. Development of an oil field is typically divided into a number of major phases namely exploration and field appraisal, development planning, project implementation and field production. For an offshore oil field development, it requires careful planning and considerations during all of the phases. The requirements for field appraisal, subsurface development planning and facilities options are reviewed. During field production, special considerations are required to manage the field. Introduction The history of first commercial oil development in Malaysia dated back to as early as 1910 when the Anglo-Saxon Petroleum Company, forerunner of the present day Sarawak Shell, developed the Miri oil field in Sarawak. From a small production of 83 barrels per day about 80 years ago, the petroleum industry in Malaysia has grown into a multi-billion dollar business. The industry underwent a dramatic expansion with rapid intensification in exploration and development. As of 1 January 1994, a total of 883 exploration wells have been drilled in Malaysia resulting in the discovery of a total of 99 oil fields. At present, 32 oil fields are in production. The present producing oil fields are located offshore Peninsular Malaysia, Sarawak and Sabah (Figure 1). Offshore oil field development requires special consideration during the exploration, appraisal, field development, project implementation and field production phases. The scope of work and capital expenditure is generally greater for an offshore field development. The development requires a long project lead time before the first drop of oil can come onstream. In addition, the oil reserves and well productivity need to have certain threshold value to offset the greater expenditure (capital/operating) and long project lead time. More detailed study are required, especially in the areas of reservoir data acquisition. This paper attempts to identify the critical factors that need to be considered during the major phases of oil field development namely exploration, appraisal, field development, project implementation and field production. The subjects that will be discussed are based on Malaysia's experience. EXPLORATION AND APPRAISAL Exploration Considerations Drilling an offshore wildcat well can incur a substantial expenditure. In Malaysia, generally, this can range from RM$5 to RM$15 million, depending on the well depth and production tests requirement. Hence, it is of great importance to properly assess all the available data and information before committing to drilling of an exploration well, which carries an element of risk. P. 475

This paper presents the challenges faced by PETRONAS in ensuring a secure and sustainable gas supply to meet the market demand for the PGU project. Key to the success are good knowledge and understanding of gas demand trends, integrated long term gas fields development planning, and early identification of future gas supply challenges. Gas demand projections and current observed trends, trends of existing gas development projects and environments surrounding future gas development are discussed. Technologies and strategies that are expected to have a positive impact on future developments are also discussed. The information provided in the Paper supports the following observations and conclusions;realistic gas demand forecast is essential to ensure that supply capacity matches the demand;integrated long term gas fields development planning requires consideration of gas market, available delivery capacity, technical readiness of the field, available pipeline and processing capacity ullage to tie-in other fields, ability to provide security of gas supply to meet demand fluctuations, requirement to provide infrastructure for possible tie-in of future gas fieldsthe challenges of future gas supply are to develop smaller gas fields, gas fields located in remote location, gas fields having high CO2 content and enhancing reliability of supply. Introduction Gas utilisation masterplan was conducted in 1981 to evaluate the optimal utilisation of natural gas for the benefit of the national economy. The main focus of the evaluation was to maximise utilisation of natural gas towards reducing Malaysia's dependence on crude oil and petroleum products, providing security of energy supply at prices that would be attractive to support the Government's programme for industrialisation and minimising the wastage of associated gas. Gas utilisation for petrochemical and fertilizer industries for domestic and export market prospects was also analysed. A center piece of Malaysia's energy diversification effort is the implementation of Peninsular Gas Utilization (PGU) project, the biggest domestic gas scheme in South East Asia. The PGU project is an integral part of Malaysia's economic development plans and involves the construction and installation of facilities to enable the production, processing and transmission of gas to end-users throughout Peninsular Malaysia. PETRONAS, the national oil company and custodian of the petroleum resources, is responsible for overall management of petroleum operations in Malaysia. The upstream gas operations offshore Peninsular Malaysia are managed by joint ventures between PETRONAS and PSC partners. EPMI and PCSB are currently the main operators of gas fields offshore Terengganu. The new player in upstream gas operation is IPC with the first gas delivery by late 1999. Under the present supply arrangement, PETRONAS itself purchases the gas from PSC partners and remains the owner until delivery to the customers. PGB, a subsidiary to PETRONAS acts as a throughput company to accept, process and transmit gas in bulk to PETRONAS customers. The objective of this Paper is to outline the challenges to ensure a secure and sustainable gas supply to PGU project. The Paper is structured as follows; gas demand, resources and production, existing upstream development, downstream facilities and, supply challenges. P. 481^

This paper is a review of the gas fields development in Malaysia. The major subsurface engineering considerations for gas development include drive mechanism determination, well requirement, completion strategies, well deliverabilities, recovery factor and reservoir surveillance requirements. For surface engineering, the major considerations include offshore facilities function, platform configuration and sequence and process and compression requirements. The result of the review is the summary of some of the differences in gas fields development to date. Introduction The first gas field development in Malaysia started in 1982 when E-11 field, located offshore Sarawak, was developed. In the following years, four more gas fields namely Duyong, Jerneh, F-23 and F-6 were developed. The Duyong and Jerneh gas fields are located offshore Peninsular Malaysia while E-11, F-23 and F-6 fields are located offshore Sarawak (Figure 1). The fields are operated by PETRONAS Carigali Sendirian Berhad (PCSB), ESSO Production Malaysia Inc. (EPMl) and Sarawak SHELL Berhad (SSB), all are the PS Contractors to PETRONAS, the national oil company. In Peninsular Malaysia, the first development started in 1984 when Duyong field was developed by PCSB to provide the necessary offshore infrastructure for development of gas fields offshore Peninsular Malaysia. With the increasing demand for gas prompted by the onshore pipeline network installation by PETRONAS to fuel the power and industrial sector, sales from Jerneh, EPMI's first gas platform, was initiated in 1991. Gas demand is projected to continue to grow in the near future. To meet this growth, EPMI will develop another field, namely Lawit, for production in 1997. In addition, two gas reservoirs in existing producing oil fields were also developed in 1984. However, their development will not be discussed here. In Sarawak, E-11, being the closest to shore, was the first gas field developed by SSB. Delivery of gas to shore commenced in 1982. Shortly thereafter, in 1983 the second gas field F-23, came onstream. The third and the largest gas field, F-6, started production in 1987 Produced gas offshore Sarawak is delivered to Liquefied Natural Gas (LNG) plant and fertilizer plant. A small portion was used for power generation. Another LNG project is currently under construction and will commence operation in 1995. Development of gas fields dedicated for the second LNG project is currently in progress. This paper discusses the major subsurface and surface engineering considerations for gas fields development in Malaysia. It will also outline some of the differences in gas fields development to-date. GEOLOGY OF PRODUCING FIELDS In Peninsular Malaysia, hydrocarbon accumulations are found in the Upper Oligocene - Upper Miocene alluvial-coastal plain clastics. P. 549

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