Formation damage caused by perforating is among the highest risks in well completion. This paper examines a new technology for completing wells in unconsolidated formations that installs a liner hanger and sand control mechanism in a single trip to eliminate explosive perforation charges and associated formation damage risk. In addition to eliminating perforating, the technology reduces the cost of well construction by allowing the production liner, flow conduit, primary cementing, and sand control tools to be run in a single trip.
The perfless completion system uses telescoping tubes that extend from the liner into the formation by applying hydraulic pressure and mechanical force. Once the tubes are extended (or telescoped), the liner is cemented in place. The tubes, which contain sand control media, form conduits from the formation to the casing ID. No large, high-horsepower fluid pumping treatments are required. Neither are after-completion drilling mud and fluid-loss control measures, both of which can cause formation damage. The new completion method eliminates gravel packing and minimizes intervention in completion operations, saving substantial rig time. It also simplifies operation logistics, especially in remote or offshore environments.
This new technology was developed by a Joint Investment Project (JIP) that included three major operators, a large service provider and a small technology company. This paper describes initial field test results of the new system, cost comparisons with existing methods, and expected economic benefits over the lifetime of wells in typical applications of this new technology.
Reducing or eliminating formation damage caused by perforating can result in a more productive well over its lifetime. The history of formation damage caused by perforating has been well documented. Fractured and compacted zones, perforation gun debris, and broken formation blockages are common types of damage that can occur inside the perforation tunnel. Studies have shown that conventional perforating of cased wells can cause an increase in skin values, especially over the extended lifetime of the well. Studies have also shown that increasing the depth of penetration will increase not only the skin value of the well, but also the amount of fines in a perforation tunnel.