Canada’s oil and gas player Trillion Energy has started velocity string operations on its production platform at a gas field offshore Türkiye.
The program aimed at enhancing gas production was carried out on the Akçakoca-3 gas well situated at the SASB natural gas field in the Black Sea off the coast of Türkiye, in which the Canadian firm holds a 49% stake. In addition to Akçakoca-3, the field holds the Guluc-2, South Akçakoca-2, and West Akçakoca-1 wells.
According to the Canadian player, the latest velocity string initiative involved replacing the existing 4 ½” production tubing with 2 3/8″ tubing, described as a crucial step for ensuring long-term stable gas production and addressing water-loading issues.
The Alcatras workboat was contracted to transport essential heavy equipment to the Akçakoca production platform. Afterward, the equipment was loaded onto the Şirinbaba boat for transport to the platform. This included wellheads, two tubing head spools, two Christmas trees (XMT), and other equipment, such as a blind flange, high-pressure hoses, adapter flanges, elbows, and 2-3/8″ tubing.
On October 22, equipment was transported and installed at the Akçakoca platform. A blind flange was installed above the tubing head spool and a 2-1/16″ 5M gate valve and a 2-1/16″ 5M x Fig1502 connection were attached to the tubing head spool outlet.
Next, additional equipment was loaded onto the Alcatras workboat, including velocity string tubing, HP and suction pumps, tubing dope, and hoses. Some of the key operations in this stage included closing the lower master valve (LMV) to manage gas flow, removing the old XMT to install the new tubing head spool (THS), optimizing gas flow by connecting hoses to the production line, and cleaning operations to ensure system integrity before resuming gas production.
The velocity string tubing and other equipment dubbed essential arrived at the platform on October 24, with the snubbing unit, which set off from Romania in early October, clearing customs and arriving at the port for transport to the Akçakoca platform a day later. The unit was then transported to the platform and assembled by the Snub Co. team, contracted to install the velocity strings. Afterward, the rig was connected to the Akçakoca-3 gas well.
The official start of operations on the Akçakoca-3 gas well on October 27 marked the beginning of the firm’s “highly anticipated” SASB velocity string program. Akçakoca-3 was spudded the next day, with the wireline entry guide, first joint, and first burst disc connected. Following these preparations, the velocity string was introduced into the wellbore.
This content is available after accepting the cookies.
The Akçakoca-3 gas well has been spudded, with the wireline entry guide, first joint, and first burst disc successfully connected. Following these preparations, we have begun running the Velocity String into the wellbore, with tubing now being lowered. $TCF ?? $TRLEF ?? $Z62 ?? pic.twitter.com/wZGzndUTKa
The program was completed on October 30, when the snubbing unit was moved to West Akcakoça-1. The firm intends to divulge the results of the measuring as soon as it has been completed.
This content is available after accepting the cookies.
Velocity String installation on the Akçakoca-3 gas well has now been completed; results are currently being measured, which will be announced soon. The snubbing unit has now been transferred to the West Akçakoca-1 gas well. $TCF ?? $TRLEF ?? $Z62 ?? pic.twitter.com/LlZi6WexUi
The velocity string program forms part of the second stage of the workover program intended to revitalize the field and sustain long-term natural gas production. Phase 1, which entailed perforation operations , was completed in mid-August .
At the time, two wells stabilized – South Akçakoca-2 and Guluc-2. As for the remaining two, West Akçakoca-1 had not stabilized due to some irregularities. Gas flow did not initially occur at Akçakoca-3 following perforation, but the firm was optimistic about its start of production as the wellhead pressure (WHP) steadily increased.
In early September, Trillion shared that the WHP for Akçakoca-3 had increased to 616 psi by September 6 and the well was put into production. Initial production flow rates totaled 4.28 MMcf/d, increasing to 4.66 MMcf/d, with WHP reaching 645 psi.
Another well – Alapli-2 – was opened to test pressure resulting in gas flow to the surface. While it was not producing gas in significant quantities at the time, production was expected to start following the installation of velocity strings.
“We are thrilled with the strong performance of Akcakoca-3 and the successful flow tests at Alapli-2,” said Arthur Halleran , CEO of Trillion Energy. “All the wells except Bayhanli-2 have now been put on production or flow tested to ascertain if gas is present and capable of production in the 4 ½” production tubing. This confirms that once the 2 3/8” is installed in the wells the gas will flow in a predictable and stable manner.”
In early October, the firm reported Akçakoca-3 and South Akçakoca-2 averaging 2.55 MMcf/d and 2.3 MMcf/d in the previous 30 days. Guluc-2 and West Akçakoca-1 were only producing intermittently due to water loading, with Guluc-2 averaging at 1.7 MMcf/d over the previous two-month period.