Abstract

Supercritical Carbon dioxide (SC-CO₂) has many excellent properties, such as high rock-breaking efficiency, strong dissolved performance and good displacement efficiency. It is a high-efficiency fluid to exploit coal-bed methane, shale gas, heavy oil, low permeability reservoirs and other unconventional oil and gas reservoirs. Using SC-CO₂ jet to break formation rock assisted the drill bit can get several times the penetration rate of conventional drilling and effectively enhance the oil recovery while achieving an initiative reduction of greenhouse gas by storing the CO₂ underground in the proper unconventional reservoirs. The functions and process of drilling and completion experimental system are designed based on the SC-CO₂ fluid properties and the actual operation conditions. Tests find that the remote control of the system is reliable, pressurization process is steady, sealing and operating performances are excellent. The system can effectively simulate the actual drilling and completion process with SC-CO₂. The rock-breaking performance of SC-CO₂ is much better than high pressure water jet which verifies the application superiority of SC-CO₂ in rock-breaking drilling. The research lays basis for the development of SC-CO₂ drilling and completion technology.

Keywords:

Carbon dioxide, completion, drilling, supercritical,

References

Competing interests

The authors have no competing interests.

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The authors have no competing interests.