Successfully Application of RPM in Sand Control Treatments for Offshore Field: Challenges, Results and Improvements

Abstract

Abstract One of the offshore gas fields, the formations are comprised of mixed deltaic and young shallow marine clastic sediments, which are considered among the shallowest unconsolidated and poorly sorted formations, with a high percentage of fines. Along with the sand production issue is the multiple stacked reservoirs that consist of interbedded sand-shale and laminations having undergone gas-water contact (GWC). The proximity of a water leg to the gas column also indicates likelihood of early water production. Water breakthrough can cause significant reserve loss in the gas reservoir and can be even more serious in the sand control completion, which creates a challenge when the two problems combine water and sand. Typical sand control treatments were high-rate water packs (HRWPs) and Extension packs (ExtPacs) or fracture for placement of proppant (FPP). The use of a pad is necessary to maximize the amount of proppant placed into the formation and help reduce overall skin using onsite data analysis. The gravel pack carrier fluid is a viscosified system with shear thinning rheological properties and efficiently suspends sand in static condition. Additionally, this fluid allows substantial flexibility in sand control design for varying degrees of sand support for gravel packing, fluid-loss control, friction-pressure reduction, and a low-damage fluid system (validated with laboratory testing using reservoir cores to validate return permeability values). The objective of the relative permeability modifier (RPM) in sand-control chemical treatments is to prolong hydrocarbon production over time using effective control of water production in one step as a prepad fluid, eliminating the cost and complexity of the water shutoff treatment stage later as part of well life Applying the RPM process has not only reduced water production in these areas but has also resulted in more gas cumulative production. It is also important to monitor production for several months after the treatment to determine the success or failure of the application. Globally, this is the first successful application of RPM delivery in the same aqueous gravel-packing carrier fluid system using a pad fluid, consisting of high-grade xanthan polymer as a gelling agent. Implementation of this process provides the operator an additional tool to increase the possibility of hydrocarbon production from a reservoir that has not been considered viable. Use of the RPM technique in sand-control completions also an option to treat wells after sand-control treatments and control water production resulting from nearby GWC