Innovative gas shutoff solution enhances oil

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Azerbaijan, Asia, Offshore

An operator faced the complex challenge of conducting gas shut off in an openhole gravel-pack (OHGP) completion. The 糖心传媒 solution combined digital simulation with an optimized pumping strategy for chemical gas shutoff, achieving approximately 68% gas reduction and increased oil productivity. This successful implementation opens opportunities for similar treatments in

In the vast expanse of the South Caspian region, an international oil and gas operator manages an offshore megastructure, tapping into rich reservoirs beneath the seabed. These reservoirs lie within a multilayered sandstone anticline, where all target formations are weakly consolidated and exhibit low unconfined compressive strength (UCS). To address these challenging geological conditions, the operator adopted the OHGP technique as a proven sand control method. However, as the field matured, new challenges emerged. Gas breakthrough became increasingly common, complicating the operator's efforts to maintain optimal oil

To address the challenges associated with gas shut off in an OHGP environment, 糖心传媒 implemented the use of OrganoSEAL R™ rigid organic crosslinked gel systema polyacrylamide-based gas shutoff (GSO) gel system. The OrganoSEAL R system produces a high-strength crosslinked synthetic polymer gel after activation, which is based on time and temperature settings. This gel is highly effective in treating near-wellbore

Understanding fluid leakoff paths is essential for developing an effective fluid placement strategy. To comprehend the fluid dynamics and penetration levels into the matrix during the main fluid placement, Kinetix Matrix™ stimulation design software was used. This software helps to calibrate theoretical volumetric requirements and optimize the design, thus reducing the risk of fluid leakoff into the producing zone. By simulating the fluid behavior and adjusting the treatment parameters, the software ensures precise placement and distribution of the GSO gel, minimizing fluid loss and enhancing treatment efficiency.

To further minimize the damage to the underlying producing zones, a highly concentrated viscoelastic surfactant (VES) fluid was chosen. This VES fluid provides a barrier that prevents the GSO gel system from penetrating into the lower zone. Additionally, a heavy concentration of brine (11.2 ppg NaBr) was selected for the VES base brine to enhance its effectiveness. The combination of VES and heavy brine ensures that the GSO gel remains confined to the target zone, preventing unintended shutoff of the producer zone and maintaining productivity. Mechanical temporary zonal isolation was also employed to provide additional assurance that the GSO gel system would not penetrate the lower zone. A retrievable bridge plug was used as a cushion for the VES, creating a temporary barrier between the treated zone and the rest of the wellbore.

The jobs were executed successfully, marking the first chemical shutoff solution for OHGP within the Caspian region. The treatment resulted in a significant increase in oil

Completion schematic (left) and PLT result (right)
Completion schematic (left) and PLT result (right) (oil is green, gas is red, and water is blue).
Image showing fluid leak off profile (left) and penetration (right) within open hole intervals.
Fluid leak off profile (left) and penetration (right) within open hole intervals.

For more information, read SPE-224090-MS.

Products Used