Industry First Openhole Alternate Path Gravel Pack Completion in HPHT Environment: Fluid Development and Case History

Abstract

For offshore wells requiring sand control, Open Hole Gravel Packing (OHGP) with or without shunted screen technology is a common completion technique. Prior to this paper, there has been no application of shunted screen OHGP in High-Pressure High-Temperature (HPHT) environment due to lack of a viscous fluid availability in high-density divalent brines (> 14.6 lbm/U.S. gal). For the case study, the fluid requirements in terms of density and temperature were 15.4 lbm/U.S. gal and 265°F, respectively. The only brine option at this density was a blend of calcium chloride/bromide and zinc bromide. In this brine and density, none of the existing fluids work hence a novel polymer-based fluid had to be developed. The fluid had to pass the following tests a) rheology before and after subjecting to high shear of both uncontaminated and contaminated fluids at 3 different temperatures b) sand settling tests at 4 different temperatures c) Production Screen Tester to ensure the fluid does not plug the screens during the job. System Integration Tests (SIT) were performed to ensure the mixing equipment would be able to batch mix the fluid and actual pumping equipment would function properly with the fluid. The field trial planning included simulations, pre-job meetings, and fluid management plan. The job was executed as per the procedure outlined during pre-job meetings. This paper discusses laboratory development, yard test qualification, and successful shunted screen OHGP case history of a novel 15.4 lbm/U.S. gal viscous gravel pack carrier fluid.

Simulation and application analysis of gravel packing in deepwater HT/HP wells

“…Both of these conditions can lead to premature plug and pack failure, which can make the packing process very complicated and difficult to control. [10][11][12][13] In extreme situations, such as significant temperature variation of the deep water reservoir (low temperature near the mud line → HT in a deep reservoir), low fracture pressure at high-pressure (HP) formation, and medium and high permeability, gravel packing operation faces extremely high operational risks and key technical difficulties. Mainly because high porosity and high permeability lead to large sand production, and low fracture pressure at HP formation leads to narrow operation windows.…”

“…If the pump rate is low and the gravel transport is not efficient, a premature bridge can occur. Both of these conditions can lead to premature plug and pack failure, which can make the packing process very complicated and difficult to control 10–13 …”