Since 1984, Peninsular Malaysia's gas fields have followed a distinct operational philosophy. In the initial field development, sand production was not considered a concern, resulting in wells and facilities without designs for sand management. Consequently, wells are confined to their maximum sand-free rate. Conversely, with reservoir pressure depletion, wells are beaned up to enhance drawdown, inadvertently introducing sand into the wellbore. This necessitates a delicate balance between sustaining production and managing sand effectively. This paper delves into how a highly sand-sensitive asset in Peninsular Malaysia's gas field navigates this challenge through the adoption of risk-based approach to sand management.
The adoption of PETRONAS Carigali management guideline, aims to transition assets to a risk-based strategy, avoiding well shut-ins upon surface sand detection. Sand severity matrix was mapped as the initial analysis to assess sand erosion and transportation risks. Addressing sand issues starts with downhole management in wells lacking primary control. Remedial measures such as through tubing erosion-resistant sand screens, are installed. Following installations, monitoring enhancements involve acoustic sand sensors and online sampling, facilitate swift responses to sand surges, especially in satellite platforms. Acknowledging that sand controls may not entirely filter sand downhole; fines are managed through a closed loop online sampling. To identify flowline defects from sand erosion, radiographic and ultrasonic testing, especially at hotspots, is employed. Notably, routine pigging ensures a comprehensive approach to sand management within the platform.
Field A led the way as the initial field in Peninsular Malaysia to pilot the adoption. With downhole sand control in wells producing sand, along with acoustic sensors and an online sand sampler, Field A saw 30% production increment, matching peak production in 2019. Despite success, one well continued producing fines below 45 microns. Sand erosion analysis tool indicated minimal erosional rate within limits, further confirming with ultrasonic and radiographic testing, UT/RT done previously, allowing the well to flow with risk assessment. This served as a pivotal milestone, where wells were previously restricted even with insignificant sand presence. Post-sand screen installations, pigging operations showed minimal sand accumulation in pipelines. Planned UT/RT inspections at each flowline will provide further insights.
In mature fields, the occurrence of sand production becomes inevitable. By incorporating downhole sand control, real-time sensors, online sand sampling, continuous flowline integrity monitoring, and regular pigging, operators can proactively manage sand production in the long run. This strategy enables the optimization of production while mitigating the risk of equipment damage or operational disruptions stemming from sand-related challenges. A field that, for the past decade, maintained zero tolerance for sand is now transitioning to an acceptable level of sand production. Addressing sand management solely downhole is insufficient; comprehensive measures on the surface are required, fostering accountability across all parties to facilitate the transformation of a sand-sensitive asset.
