Dual String DIAL System Successfully Installed for Offshore South East Asia Operator

Dual String DIAL System Successfully Installed for Offshore South East Asia Operator
Case Study

A pilot DIAL installation campaign was initiated between Silverwell and an offshore operator in South East Asia. The five well program consists of three single string and two dual string wells across multiple fields. The purpose of the program is to test the DIAL system in a multitude of operating conditions, including high deviation deployment, proving DIAL’s digital production optimization and interventionless capabilities ahead of a wider adoption strategy. A dual completion well was installed in November 2020.

Client Challenge

The operator has many offshore dual completion wells which require continuous supervision to ensure optimum production. This is extremely challenging for dual string wells which are operated with conventional PPO (Production Pressure Operated) valves which tend to multi-point and shallow inject. Gas robbing by the less productive string is also common due to a lack of downhole control. This can lead to minimal or no gas injection in the stronger string resulting in lost production. This challenge is further magnified by the low surface casing pressure available in this field.

The operator has several high angle wells. Expensive tractor well intervention is required to change conventional valves that are deployed at high angle (>70°). In the wells where permanent downhole gauges are not installed, the operator relies on flowing gradient surveys to determine well performance and injection depth.

DIAL System Solution

This new drill well was completed with two 3-1/2” completion strings inside 9-5/8” casing (47ppf). The top perforation was at approximately 6,000 ft. MD and the maximum inclination was 63 degrees. Silverwell, in close collaboration with the client, devised a gas lift design to maximize the use of the low casing pressure.

On the short string, three DIAL Gas Injection Units were installed to approximately 2,800 ft MD. On the long string, three DIAL Gas Injection Units were installed to approximately 2,600ft. MD.

A DIAL Sensing Unit was installed on the long string below the packer at approximately 5,500ft MD. The DIAL Sensing Unit features two independent sensors to measure production parameters from each formation. These bottom hole measurements are analyzed to determine the optimum injection rate for each string.

Each DIAL Gas Injection Unit features three orifice ports which can provide injection rates ranging from approximately 300 MCF / Day to 1100 MCF / Day. Due to the strong reservoir drive, gas injection is forecast to be at the third DIAL unit on each string for the foreseeable future. Below the DIAL Gas injection Units, two dummied SPM’s are installed for the later phases of the well’s life.

Considered by the operator to be the most complex intelligent completion it had ever installed was successfully completed, without incident, in November 2020. This accomplishment paves the way for future dual string implementation with an estimated production increase of up to 40% enabled by the DIAL System’s downhole digital valve control.

DIAL Results

Forecast 40% Production Increase

Continuous and optimized allocation of available lift gas between dual producing strings forecast to radically increase production.

Operational Flexibility

Due to COVID-19 restrictions, the well was completed with a local operations crew with Silverwell providing remote technical support throughout.

Collaboration and Partnership

Silverwell, its local partner and the operator harvested a strong relationship during the design, planning and installation phases of the project to enable a successful implementation of a highly complex well completion.

“Silverwell successfully completed the most complex dual string intelligent gas lift well.”

DIAL Data

Tubing 2 x 3.5” 9.2 lb/ft
Casing 7” 29 lb/ft
DIAL Depth 6,000ft. MD
Bottom Hole Pressure 2,000 Psi
Bottom Hole Temperature 70 °C
Casing Head Pressure 750 Psi
Well Head Pressure 200 Psi
Gas Lift Injection Rate 500 MCF Day

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