Sinergia S.p.A. has developed in partnership with Inntech srl, a Patent Pending system able to automatically pressurize and depressurize the TCA (tubing- casing-annulus), constantly regulating the pressure through pre-determined ramps, within the design range of the oil well.

The tubing-casing-annulus (TCA) is the empty space (trapped) between the production tubing and the smaller casing string in an oil and gas well.

The TCA takes its name from the corresponding geometric concept of a ring, which is the region/ring between two concentric circles. 

THE TCA PRESSURE VARIATION

It depends on the following factors:

• Critical Causes: Leaks from seals (packer, wellhead, and completion accessory), tubing/casing connections, or poor cement bonding behind the casing can lead to pressure anomalies in the Tubing-Casing Annulus (TCA). These are considered critical issues and must be promptly identified and addressed.

• Well flowing condition: TCA pressure begins to increase as the well starts to flow. This pressure buildup is directly proportional to the production flow rate and is primarily attributed to the thermal expansion and compression of fluids within the TCA.

While critical causes require immediate detection and remediation, flowing conditions—especially in wells equipped with Electrical Submersible Pumps (ESP)—can also result in significant TCA pressure increases. ESPs generate higher flow rates, which can exacerbate thermal effects and lead to a substantial rise in annular pressure.

If TCA pressure approaches or exceeds the Maximum Allowable Annulus Surface Pressure (MAASP), critical well components such as wellhead crosses, packers, tubing, and casing may be compromised, potentially resulting in severe operational and safety consequences. Additionally, in wells with ESP installations, manual depressurization of the TCA must be performed with caution. A rapid release of pressure by the operator can lead to explosive decompression, which may damage the power supply cable, compromise insulation integrity, and render the ESP system inoperable.

Main advantages compared to actual avalaible technology:

• Skid units for easy transportation.
• Human error elimination.
• Double Feed system liquids-nitrogen.
• Complete control of TCA pressure (pressure unload or download).
• Fine regulation of TCA pressure to handle the well with ESP installation.
• Pressure ramp can be set according to well features.
• Modbus connection to Client system.
• Remote software updating and control.
• MAASP control.
• Bleed off in closed loop (no emission in atmosphere).
• HIPPS system to protect the unit (Well head rating).
• Mass balance and volume control (optional).
• Bleed off flow density control that means to detect leakage in the TCA and to reduce close to 0 the pollution.
• Very low maintenance.
• No operator required after commissioning and tuning phase.
• SCADA system and data records.
• Connection of well parameter (WHP, WHT, ESP frequency ect.) to implement Artificial Intelligence with possibility to study the different scenario of ESP failure.

Inntech srl, a company based in Basilicata (Italy), is the only authorized company to handle the installation and fine tuning of the system.