Pattani Basin

Introduction

Located in the Gulf of Thailand, the Pattani Basin has been a significant contributor to the country’s oil and gas production since the 1960s. Though small in size compared to prolific basins in the Middle East and elsewhere, the Pattani Basin helped establish Thailand as a hydrocarbon producer through the development of major offshore gas fields. Sustained activity led to the Basin reaching peak output by the early 2000s before maturation and decline set in.

The shallow water Pattani Basin was an early offshore success for the region. Initial exploration in the 1960s by foreign companies revealed sizable natural gas reservoirs accessible from fixed platforms. This galvanized Thailand’s nascent offshore industry and led to billions of cubic feet of gas production over subsequent decades. Further investment and drilling brought additional discoveries and enabled the maximum development of resources.

In recent years, focus has shifted to boosting oil output and applying advanced recovery methods to prolong the life of Pattani Basin assets. Though production has waned from peak levels, the Basin still supplies vital domestic gas and oil volumes today. Operators continue to leverage technology to optimize the mature fields.

This article provides an overview of the exploration history, development milestones, and current status of the Pattani Basin. The story highlights how this offshore area helped launch Thailand into the ranks of oil and gas producing nations in the region. While its best years may be behind, the Basin remains an important part of the energy supply portfolio.

Early Exploration and Discoveries

Exploration activities in the Pattani Basin began in the early 1960s, led by the Royal Dutch/Shell Group which operated a concession in the Gulf of Thailand. Drilling the first exploration well in 1961, Shell made a sizable natural gas discovery at the Erawan field in 1971. This discovery confirmed the hydrocarbon potential of the Basin and its geological continuations with the Malay Basin across the border. Further exploration in the 1970s by Shell and new entrants like Unocal revealed additional major gas fields including Funan, Satun, and Platong. Significant volumes of natural gas were discovered in shallow reservoir formations, typically at depths of around 3,000 feet below the seabed. The relatively shallow waters of around 50 meters enabled the use of conventional fixed platforms, allowing rapid development of the commercial discoveries. The series of successful finds established the Pattani Basin as a globally significant gas province and helped position Thailand as an emerging regional energy player.

Expanding Interest and Peak Production

The major natural gas discoveries of the 1960s and 70s sparked greater interest in the Pattani Basin’s potential, bringing increased investment and drilling activities in the following decades. In addition to Shell and Unocal, other international firms including Total and Japan Petroleum Exploration Company entered the area. Thailand’s national oil company PTTEP also became a key explorer and producer. This resulted in the installation of nearly two dozen fixed platforms and hundreds of development wells by the 1980s. Gas production from the Pattani Basin grew steadily, reaching peak output of over 1 billion cubic feet per day in 2001. Total gas production from the Basin reached 4 trillion cubic feet by the early 2000s. The Pattani Basin gas resources, along with connected fields in the Malay Basin, became critical to meet Thailand’s rising energy demand and also enabled gas exports.

Decline and Efforts to Maintain Output

By the early 2000s, many fields in the Pattani Basin began exhibiting maturity and production decline after decades of exploitation. Efforts shifted to maximizing recovery and output from existing assets through workovers, infill drilling, and enhanced oil recovery techniques. Focus also turned to boosting oil production, which had taken a backseat to gas development in previous years. Improved 3D seismic data allowed exploration for deeper objectives, with some smaller oil discoveries made in formations below 2,000 meters. Operators like Chevron applied steam flooding to boost recovery rates. While oil production increased to around 25,000 barrels per day, overall output was well below peak levels. Nevertheless, companies continue to leverage technology and innovation to slow decline rates and wring additional resources. The Pattani Basin still contributes vital domestic gas and oil volumes today.

Current Status

The Pattani Basin today is considered a mature oil and gas province, with exploration and development activities focused on optimizing recovery from existing offshore assets. Approximately 15 fixed platforms remain active, down from nearly 30 in the 1980s. The Basin now contributes around 20% of Thailand’s total natural gas production and 5% of oil output. Major operators include Chevron, PTTEP, and Malaysia’s Petronas Carigali. While fields are in decline, production is being maintained through workovers, infill drilling, compression, and pumping upgrades. Enhanced recovery techniques will be increasingly applied to boost outputs. Exploration is also ongoing for deeper objectives and in untested areas, though large new discoveries are unlikely. The Pattani Basin remains a key part of energy supply for Thailand, benefitting from sustained efforts to slow decline rates and maximize recovery.

Outlook

While the Pattani Basin is well into maturity, operators continue to deploy innovations to extend the productive life of the offshore assets. Advanced seismic imaging and reservoir modeling will help identify remaining pockets of resources within older fields. Enhanced oil recovery methods, such as chemical injection, horizontal drilling, and hydraulic fracturing, can increase recovery factors. Further tie-ins of nearby satellite reservoirs can boost outputs. Ongoing exploration also holds potential for incremental discoveries, though likely smaller in scale. Field optimization programs will become increasingly critical to sustain production. The Pattani Basin still holds substantial remaining gas and oil volumes that can support Thailand’s energy needs for years to come. Maintaining output will require leveraging the latest technologies and creative development approaches in this mature province.

Conclusion

The Pattani Basin has played an integral role in the emergence of Thailand as an oil and gas producer within Southeast Asia. Early exploration success in the 1960s and 70s led to significant development of the Basin’s shallow water gas reserves. Sustained activity over subsequent decades brought peak production levels, supplying vital energy supplies for Thailand’s growth. While maturation has set in, the Basin remains a core part of the offshore portfolio through efforts to maximize recovery. Continued innovation and technology applications will be key to prolonging output from the aging fields. The Pattani Basin represents an important chapter in Thailand’s hydrocarbon history, helping transform the country into a regional energy player. Though past its prime, the Basin is still contributing essential domestic production through the skillful management of its resources.