Sakarya gas field is located in the in Turkish Black Sea. (Credit: Türkiye Petrolleri Anonim Ortaklığı)
Subsea7, in a consortium with OneSubsea, SLB and Saipem, won EPCI contract for the second phase of the Sakarya field development. (Credit: SUBSEA7)
The construction of project’s pipelines commenced in 2022. (Credit: Türkiye Petrolleri Anonim Ortaklığı)

The Sakarya gas field in the Turkish Black Sea is being developed in two phases. The Sakarya Gas Field Development Phase II refers to the second stage development of the field, which hosts the largest gas reserves of Türkiye.

The project will be executed by Türkiye Petrolleri- Offshore Technology Center (TP-OTC), a fully owned subsidiary of Türkiye Petrolleri Anonim Ortaklığı (TPAO).

Sakarya field is expected to have a production capacity of 10 million cubic metres of natural gas per day in the first phase of the project, which involves drilling of ten wells. At full capacity, the project will produce 40 million cubic metres of natural gas per day.

The annual production will also increase from 3.5 billion cubic metres (bcm) in Phase I to 14 bcm in Phase II.

The Sakarya gas field is expected to meet around 30% of Türkiye’s total domestic natural gas demand and enable it to reduce natural gas imports significantly.

Türkiye commissioned the project in April 2023 and began gas production from the field. The Sakarya Gas Field Development Phase II may become on stream in 2027.

Sakarya Field Location Details

The Sakarya field is located in the western part of the Black Sea, around 165km offshore from Filyos, in Zonguldak province.

The field is within the Sakarya Gas Field Block C26 in the exclusive economic zone of Türkiye. The maximum water depth at the site is around 2,200m.

Sakarya Field Background

The Sakarya Gas Field was the first deepwater gas field discovery in the country. The field was discovered in August 2020 by Tuna-1 well.

Initially, the natural gas reserves were estimated to be 320bcm /11 trillion cubic feet (tcf) of lean gas.

Following the second discovery in October 2020, the potential reserve estimate was increased to 405bcm (14.3tcf) of lean gas.

In 2021, an additional 135bcm gas was discovered through the drilling of the Amasra-1 exploration well.

The Sakarya field is expected to host a total of 540bcm of gas.

In February 2022, TPAO carried out the second flow test of Turkali-1 appraisal well in the Sakarya Gas Field.

The second reservoir section (R1) flowed gas at 0.62 million metric standard cubic metres per day (MMSCMD). These flow tests were conducted to optimise the development work and improve front-end engineering and design (FEED) work.

Sakarya Gas Field Development Phase II Details

The Sakarya project includes a subsea gas production system in the gas field; a gas receiving and processing terminal in Filyos Industrial Zone in the Çaycuma district of Zonguldak province; a pipeline to transport gas from the field to the terminal; another pipeline for mono-ethylene glycol (MEG) transportation from the Filyos facility to the field; and an umbilical, all including shore crossings.

In Phase II, the field will be connected to the subsea production system with up to 30 additional wells. This will increase the number of wells to 40, including ten from Phase I.

The second phase will also involve the installation of a 24-inch or above pipeline to transport the additional gas produced by the offshore field.

The onshore production facility will process the gas, following which the gas produced will be measured at a Fiscal Metering Station (FMS) and transported to the national grid through a 36km onshore pipeline.

The FMS and the pipeline will be operated by Petroleum Pipeline Corporation (BOTAŞ).

Contractors Involved

In May 2023, Subsea7 and its partner in Subsea Integration Alliance, OneSubsea, along with SLB and Saipem, won the engineering, procurement, construction, and installation (EPCI) contract for the second phase development of Sakarya Gas Field.

The integrated scope of the contract includes subsea production systems (SPS), subsea umbilicals and flowlines (SURF).

Subsea7 will perform EPCI of approximately 37km of infield flowlines, 47km of control umbilicals and associated subsea equipment. The company’s share of revenue in the contract is more than $750m. The contract also includes additional FEED studies and options to extend the work scope further.

Subsea7 office in Istanbul, Türkiye, will manage project management and engineering.

The offshore activities are expected to be carried out between Q2 2025 and Q3 2025, with optional scope between Q4 2026 and Q4 2027.

Saipem will be responsible for the EPCI of a 16-inch 175km long pipeline. The company is expected to use its flagship vessel Castorone for the installation of the pipeline in 2024.

Turkish industrial manufacturer ERGIL supplied sand treatment package to TPAO for the offshore gas project.

In July 2023, Steel pipe manufacturer Tenaris secured the contract to supply pipes and services for Phase II-A of the project. As agreed, Tenaris will supply 46,000 tonnes of 16-inch seamless pipes from its plant in Italy. The deliveries are expected to be completed by the end of 2024.

WSP Golder served as the consultant for the project’s Environmental and Social Impact Assessment (ESIA) report.