West Rustavi is an onshore oil and gas field being redeveloped in the Kura Basin in Georgia. Block Energy, a company focused on oil and gas production and development in Georgia, operates the field with 100% interest.
The West Rustavi field was discovered in 1988 and brought on stream in the same year. However, production ceased in December 1990 due to lack of funding and political instability caused by the collapse of the Soviet Union followed by the civil wars in Georgia.
Block Energy plans to exploit the field’s remaining oil and gas resources by reactivating the existing wells. It started oil production at West Rustavi by drilling two horizontal sidetrack wells in 2019.
The company also announced first gas sales at West Rustavi in February 2021 after it completed the construction of an early production facility (EPF) to enable gas production at the field in November 2020. The EPF has the capacity to accommodate as many as six production wells.
Block Energy picked up 5% stake in the West Rustavi licence from Georgia Oil and Gas (GOG) in June 2017 and acquired an additional 20% working interest in June 2018. It further increased its interest from 25% to 100% through a three-staged acquisition concluded between March and July 2019.
West Rustavi location, development history and reservoir details
The West Rustavi field spans 37.75km2 in the Kura Basin, 10km south-east of Tbilisi, Georgia. The onshore field development involved drilling as many as 13 wells. It produced 41,000 barrels of light sweet crude during the initial phase of production from October 1988 to December 1990.
West Rustavi was estimated to contain 900,000 barrels of gross 2P oil reserves in the Middle Eocene sandstones as of January 2018.
The contingent oil and gas resources in the Middle, Upper and Lower Eocene formations at West Rustavi are estimated to be 38 million barrels (Mbl) and 608 billion cubic feet (bcf), respectively.
West Rustavi early production facility (EPF) details
The West Rustavi EPF field has a capacity to produce three million cubic feet (Mcf) of gas a day. It currently handles the well stream from the two producing West Rustavi wells namely, WR-16aZ and WR-38Z.
The EPF is installed at the WR-16aZ well site and comprises an inlet manifold for six wells, along with separators and a gas dehydration and measuring unit. The WR-38Z well is connected to the EPF through a 3.5km-long and 75mm-internal diameter underground steel flowline.
Gas output of the EPF is sent to Georgian Oil and Gas Corporation’s (GOGC) main gas pipeline through an 8km-long gas sales pipeline owned and operated by Bago.
The crude oil produced from the West Rustavi wells is transported to a storage facility owned by GOGC.
Production from the WR-38Z and WR-16aZ West Rustavi wells was suspended in April 2020 due to the low oil price triggered by Covid-19. The two wells resumed production in January 2021 and February 2021, respectively.
West Rustavi drilling details
The WR-16aZ horizontal sidetrack well was drilled to a depth of 2,695m at the pre-existing 16a well site between January and March 2019. The WR-16aZ well delivered a test flow rate of 1,100 barrels of oil per day (bopd). It commenced production in July 2019.
The sidetrack drilling of the WR-38Z well at the pre-existing WR-38 well was completed in October 2019. Drilled to a total depth of 2,634m, the WR-38Z well commenced production in November 2019.
Drilling operations at well WR-51 commenced in January 2020 but were later aborted due to poor existing well conditions.
Block Energy drilled the WR-B1a horizontal well to a depth of 2,483m between June and September 2021. The WR-B1a well location was determined based on the 3D-seismic data obtained in 2019. Baker Hughes supported Block Energy in drilling the well.
However, the WR-B1a well didn’t produce at a satisfactory rate during production testing. Block Energy plans to perform downhole operations with a low-cost sidetrack from the same wellbore in the future.
Gas offtake agreement
Bago, a private gas trader in Georgia, agreed to purchase the gas output of the West Rustavi field in October 2019. Bago laid an 8km-long pipeline to feed the gas output of the field to GOGC’s main gas pipeline.
Crude oil storage for the West Rustavi field
GOGC signed an oil storage leasing agreement with Block Energy to provide up to 90,000 barrels of storage capacity at its storage facility near Sartichala in July 2019.
GOGC’s Sartichala crude oil storage facility is located 30km away from the West Rustavi field.
Norio Oil Company (NOC) and Georgia Oil and Gas (GOG) were contracted to provide drilling and workover equipment including the ZJ40 drilling rig and A50 workover rigs for Block Energy’s West Rustavi development project in 2019.
Block Energy signed a memorandum of understanding (MoU) with Baker Hughes to provide technological support for its drilling operations in Georgia in June 2021.
The EPI Group, an independent geoscience and geophysical consultancy, was contracted to provide sub-surface reservoir interpretation and engineering services for the project in June 2020.
Geofizyka Toruń was contracted to perform a 3D seismic survey of the West Rustavi field in September 2019.