This paper presents an overview of switching from rig-based sand control pumping equipment to a semipermanent vessel-based pumping setup. The design, installation, and implementation of a fracturing vessel for subsea sand control and stimulation will be covered in detail. The approach taken includes an analysis of benefits and drawbacks associated with rig-based and vessel-based pumping setups as well as the design and implementation of a vessel-based fracturing package. Additional topics discussed include determining specifications for appropriate vessel selection and best practices for vessel layout design to maximize the pumping fleet functionality while minimizing the health, safety, and environmental (HSE) exposure.We analyzed a case study in which a fracturing fleet based on a platform supply vessel (PSV) was implemented in place of rig-based equipment. Use of the methodology described here eliminated 17.7 rig days, 1540 offshore lifts, 46 helicopter flights, and 55 supply vessel trips over 11 wells in a subsea campaign. Additionally, due to the enhanced mobility of the vessel-based equipment package, it was possible to service two rigs with a single fracturing fleet. The switch from rig-based to vessel-based equipment resulted in an average savings of USD 1.3 million per well including rig day rates, fracturing equipment rental, and other associated costs.

This paper covers the design, execution, and evaluation of the development of the Zawtika field operated by PTTEPI in Myanmar. This includes the study of the reservoir, the selection of completion methodology, the operational challenges, and the performance of the wells. The Zawtika field development focused on the laminated Plio-Pleistocene reservoirs. The formation comprises a thick sequence of mixed deltaic and shallow marine clastic sediments. A conservative geomechanics study indicated that any reservoirs shallower than 1,700 m true vertical depth (TVD) have high sanding risks and would require an active sand control method. A batch completion campaign was planned and deployed as a mix of single-zone and stacked dual-zone cased-hole gravel packs (CHGP). A pre-gravel pack acid treatment was tailored for formations with high chlorite content and fines stabilization. A fracture- and gravel-pack service was the primary gravel pack option followed by high-rate water pack (HRWP) depending on water zone proximity or a lack of stress barrier. The sanction that was placed on the country at the startup of this campaign and the limited infrastructure in place led to various challenges during different stages of the campaign. Over 15 months, 17 wells were completed on three platforms with eight single-zone wells and nine stacked dual-zone wells. This totaled 26 zones where 10 zones were completed with the fracture- and gravel-pack service and 16 zones with HRWP. These jobs were executed on a tender assist for the first platform and on a hydraulic workover unit for the following two platforms. These were among the notable points for the campaign: First CHGP completion in MyanmarAchieved production objective with zero sand productionIntroduced the technique of pumping HRWP in sweep stages for longer intervals in MyanmarIntroduced several fluid systems in Myanmar, including a polymer-free carrier fluid, acid system with diverting agent, fluid loss pill, and clay stabilizerCompleted all wells without downtime related to delivery of products despite the remote location and logistics between multiple countriesCompleted the campaign without any HSE incident and with high operating efficiency