In oil and gas drilling operations, well control equipment refers to the general term for specialized equipment, instruments and tools required for implementing pressure control technology. It is used to promptly detect, control overflow and restore the pressure balance at the bottom of the well when the pressure of the slurry column in the well is unbalanced with the formation pressure. It is the core guarantee of drilling safety.
The main components and functions of well control equipment
The well control equipment system is usually composed of seven parts, each performing its own duties and jointly building a safety barrier at the wellhead:
1. The bop combination drilling wellhead bop is the core component of well control equipment, mainly include: the annular blowout preventer: the drilling tool can be closed shapes or empty well, can also be forced tripping operation in case of an emergency. Ram preventer: divided into whole sealing disc (no tool in well closed wellhead), half sealing gate (closed annular space when the Wells with drilling tools), shear damper (emergency cutting tool and the whole sealing the mouth of the well) and variable bore ram. Its characteristics are rapid well closure actions, safety and reliability, and it also has a well pressure-assisted sealing effect (the higher the well pressure, the better the sealing effect). Blowout preventer combinations: according to the stress level and well type, can be divided into single seal, double seal and seal three and four seal combination, from low pressure to adapt to the needs of shallow Wells to ultra-high pressure deep well.
2.The control system for hydraulic control system, including: remote console: provide hydraulic power source. The driller's console: make the driller can directly control the blowout preventer on the drill floor. Assist the console: provide additional control points. Ensure that the blowout preventer can be turned off quickly and accurately in an emergency.
3. Well control remit to throttle manifold and kill manifold as the core, including: throttle manifold: through the throttle valve control after shut-in wellhead pressure, controlled release of implementation of borehole fluid. Kill manifold: used to pump into the high pressure in well completion fluid, bottom hole pressure balance. Choke line: in case of an emergency will choke borehole fluid guide to safe area.
4. Drilling tools in the bop tools used to prevent borehole fluid along the drill hole is up, mainly includes: drill check valve (e.g., arrow, spherical, the inputting type check valve) : allow drilling fluid flow down, but can automatically shut off to prevent reverse flow. Kelly cock valve: installed on the kelly bar and bottom ball valve, channel within close tool when necessary. Bypass valve: port congestion in drilling tools provide new circulation channel.
5. Kick monitoring instrument for real-time monitoring and early warning signs, is the key to find the overflow: monitoring parameters include: drilling fluid return amount, circular pool level, when drilling fluid density, outlet temperature, the wellbore liquid level, etc. Advanced alarm real-time data acquisition and monitoring system, for early action.
6. Support the auxiliary equipment for well control operation: drilling fluid increase device: rapid increase to balance formation pressure of drilling fluid density. Mud/gas separator: separation of gas drilling fluid. Vacuum degasser: remove the free gas in the drilling fluid. Automatic filling and drilling fluid device: drill automatically to the perfusion in well drilling fluid, maintain fluid column pressure.
Special operating equipment is used for processing blowout out of control and so on extreme or special process: don't kill tripping device: under bring pressure to the string. Rotating blowout preventer: used in underbalanced drilling. Fire extinguishing equipment and dismantling wellhead tools.
Selection and development of well control equipment
When choosing well control equipment, factors such as pressure level, nominal diameter and combination form need to be comprehensively considered. The core basis is formation pressure, casing size, well type and process requirements. Is the development trend of intelligent well control equipment, automation and high-end. For instance, AI algorithms are utilized for well control optimization, 5G technology is applied to enhance real-time monitoring and data transmission efficiency, and high-performance, multi-functional, and customized products are developed to meet the demands of complex oil and gas reservoirs.
Well control equipment is the guardian of safety in drilling operations. Its design and application aim to form a multi-level safety protection system, ensuring that well surge risks can be "detected in a timely manner, controlled quickly and handled effectively" during the drilling process, preventing blowout accidents and safeguarding the safety of personnel, equipment and the environment. For drilling practitioners, having a thorough understanding of the functions of well control equipment and mastering its operation proficiently are crucial basic skills.