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This paper discussed Operator's experience on integrated downhole logging suite to diagnose multi-phase flow and to improve multi-reservoirs flow allocation in deviated wells, offshore Borneo Island. Field A is located in the West Balingian geological province of the Sarawak Basin, 140km offshore Bintulu in a water depth of 165ft. It was discovered in by Exploration Well #1 (EW#1), followed by downflank Appraisal Well #2 (AW#2) in 1982 and second Appraisal Well #3 (AW#3) in 2000, to address some of the significant subsurface uncertainties impacting on the field development plan. Phase-1 development wells (e.g. DW#1 and DW#2) was drilled and completed in 2014, with 7″ × 4-1/2″ cemented liner as lower completion across the clastic reservoirs. During pre-development in 2016, additional perforation in DW#1 oil zones were added whereas additional perforations in DW#2 oil zones were added in 2019. The two (2) relatively new wells produce commingled from several oil-bearing and gas-bearing zones. Developing highly compartmentalized multi-stacked reservoirs via simplified well completions, poses a great challenge for subsurface data acquisition when it comes to determining production allocation, managing flow assurance issues, understanding reservoir connectivity, surveillance of individual well performance and generating total field production forecasting. Conventional production logging result conducted in 2016 was unsatisfactory to explain some of the wellbore and reservoir flow peculiarities. Since it was important to know which zones contributed to the production, diagnostic of wellbore/reservoir flows and coupled with well integrity issues, Spectral Acoustic Logging with Thermo-Hydrodynamic Modeling was conducted to obtain the valuable information and to perform well/reservoir diagnostic. Remote platform location put an additional challenge to the logging campaign, as such the logging program was customized to satisfy the logging objectives while comply with HSE requirement. The collaborative approach between Operator and Service provider as solution partners, established a new finding for the formulation of remedial treatment to increase production and recovery from the wells by ensuring that each well operates to the maximum of its abilities.

In 2020, PCSB implemented the first permanent Plug & Abandonment (P&A) campaign for three Subsea wells in a gas field offshore Malaysia. The main objective of the campaign was to establish two (2) barriers for every movable hydrocarbon or overpressure bearing sand by placing laterally extended cement plug across impermeable formation with enough formation strength to handle the pressure of the formation to be isolated. The unique case of this operation was the challenges to execute PCSB's first subsea P&A operation in gas field Malaysia during pandemic situation. In March 2020, the Malaysian government imposed Movement Control Order (MCO) to curb the spread of the COVID-19. A semi-submersible rig was on-hired a week after government initiated the MCO, resulted in the rig preparation being badly hampered due to manpower management and material fabrication and delivery. PCSB was exposed to expensive rig daily rate that had to be managed. Four (4) main challenges were encountered during operation: safe protection for workers, expensive standby cost, manpower management and material fabrication and delivery. This paper, from the ‘project management’ point of view, describes the journey of managing rig operation during PCSB's first subsea wells P&A in Malaysia efficiently amidst the pandemic by reducing the impact of COVID-19 on project cost. With the experience of managing rig for subsea well operation, a complex operation in Malaysia, amidst pandemic, PCSB sharing on the experience is beneficial to provide context setting and benchmark on maintaining the efficiency of operation. Wells successfully met the objective of operation with no incident occurred, negotiated reduction on standby cost and managed to bring critical manpower on time during operation.

Water injection (WI) to improve oil production and increase reserves had been practiced in Malaysia since 1990s. Currently, around 27 fields are producing with water injection. To better manage these WI fields and gauge the relative performance of these fields, certain Key Performance Area (KPA) and Key Performance Indicators (KPI) were identified. Measurement of these KPA and KPIs serves as a yardstick to compare performance of WI fields and thus provide measures to improve collective performance by promoting replication of best practices and sharing lessons learnt. In the era of digital technology, the periodic measurement of KPA and KPI has been automated using the existing online platform which can remain accessible to all related parties. It provides a platform for data visualization with simple look forward analysis. The WI data is stored in company databank and the performance dashboard can be viewed from existing software. The team managed to overcome the challenges in completing the historical data gap and data hygiene which previously were managed manually and were not integrated. This resulted in historical evaluation of KPAs and KPIs of certain fields. This automation initiative will enable practicing engineers to identify the value leakages and proposed mitigation efforts. Some of the best practices identified such as pipeline pigging optimization, correct biocide dosage, periodic calibration of flow meter and chemical optimization already helped to reduce operating cost in certain WI fields. With these efforts, the company could reduce the operating cost significantly in year 2018. Other than data visualization, the tool provides diagnostic plots such as Hall Plot, Chan's Plot etc. for quick analysis of signs of well/ reservoir health deviations and thus solutions could be provided proactively. On seeing the initial positive results, this tool is being tried for the rest of the WI fields. This paper details how this tool tries to diagnose all sub-optimal areas within various WI project simultaneously, which leads to operational excellence and improvement in oil recovery, by identifying value leakages, providing proactive solutions with replication of thus identified best practices. Additionally, usage of this tool to rank WI performance of different projects can potentially help to initiate competition between different operators for improvement.

Relevant to maximizing oil recovery, water injection is implemented for reservoir pressure maintenance and to maximize oil sweeping. The water injection involves both surface and subsurface matters. Since the objective is reservoir pressure maintenance and oil sweeping efficiency improvement, the subsurface domain includes reservoir engineering, geology and geophysics as well as the production technology. For surface operations, the water injection operation includes water injection source, water plant operations and water injection infrastructure. Water injection bottle neck and water quality issue may occur and damage the water injection efficiency. An idea of molecule to molecule (M2M) water injection performance review is raised to conduct a comprehensive and collaborative water injection review that involving many and outreach parties such as reservoir engineers, geologists, geophysicists, operation engineers, production chemists, production technologists, maintenance engineers, production planners and process engineers. The opportunity to include technical providers, partner representatives and host government representatives is taken in order to allow an effective discussion and quicken the maturing of relevant solution proposals. Comprehensive end to end review from the point of water source up to the point of producer is done to identify problem at each point, threats and improvement opportunities at every single node within the whole chain. With the M2M, water injection performance review has effectively provided an effective collaborative working environment as well as a learning avenue for young professionals that are involved in water injection matters. Many action items are resulted from the exercise and they are having high impact including safeguarding potential cost of USD 10 million per year for the water injection plant and infrastructure operations. In the short run, no disturbances for oil production and in the long run, the oil recovery can be maximized. Due to some limitation, this paper discusses only the surface water injection operations.