Forging ahead in Guyana basin


17th November 2017 - Main component of $4.4 billion development is Liza-1 FPSO


ExxonMobil, together with partners Hess and CNOOC Ltd-owned Nexen are marching ahead with exploration and production in the Guyana basin.

The main component in the $4.4 billion Liza development is the Liza-1 floating production, storage and offloading vessel charter, awarded to SBM Offfshore, and ExxonMobil is moving ahead with studies for a second FPSO for Liza, possibly with capacity for 120,000 barrels per day.

Liza was initially confirmed as a recoverable resource of 1.4 billion barrels of oil equivalent in June 2016, but this was followed up by discoveries at Payara, 16 kilometres away and also Liza Deep, which showed additional high-quality oil.

In March, 2017, ExxonMobil said the Snoek well encounteed 82 feet of high quality oil, and this was followed by the Payara-2 well, which hit 59 feet of pay.

Most recently in October, the US giant announced the Turbot-1 well, which encountered a reservoir of 75 feet of high-quality, oil-bearing sandstone in the primary objective.

Well drilled

This latest well was drilled in 1802 metres of water in the south-eastern portion of the Stabroek Block, about 48 kilometres south-east of the Liza phase one location. Another well on Turbot is planned for 2018.

Drillship Stena Carron has moved to spud the Ranger prospect, which is in around 2500 metres of water and is the deepest wildcat yet on the play.

ExxonMobil is currently using a Petroluem Geo-Services vessel to shoot seismic intended to provide the baseline for 4D coverage of Liza and other discoveries.

The US giant has just been through a round of contractual renewals from suppliers, slashing rates by 40% for items such as drill fluids and cementing, with Halliburton losing some of its early dominance in the region.

An extension on the Stena Carron contract is understood to have lowered the dayrate to around $250,000.

ExxonMobil has also chartered the drillship Noble Bob Douglas for a three-year stint drilling development wells.

Elsewhere in the offshore, Tullow Oil recently shot 3D seismic in the Orinduik block, but is equally focused on its 30% participation in the Repsol-operated Kanuku block, where the partners see good prospectivity for medium-sized discoveries up-dip from the Liza trend.

“Its just a matter of finding oil-bearing sands. Liza has not captured all the oil. Some of it migrated up-dip. Are we going to find 2 billion barrels? No. But if we find 300 million in shallow water... perfect," a manager with Tullow Oil commented.

Tullow has also expressed formal interest in initiating negotiations to acquire exploration rights in an onshore area in the Takatu basin, deep in the forested interior of southwestern Guyana.

This request met with a cautious response because Guyana wants to set rigorous standards in environmental and community relations management.

The region was the location of the Karanambo-1 well, drilled in 1982 by Home Oil Company, where light oil shows were detected but with geological characteristics that are mainly naturally fractured reservoirs.

Other wells drilled in the Takatu basin are Lethem-1 in 1980, Turantsink-1 in 1992 and Apoteri K2 in 2011.

Kenya success

Tullow’s application cites its successes in Kenya in similar shallow-basin geological formations and expresses confidence in the prospectivity of a basin that spans 5500 square kilometres.

Guyana’s Environmental Protection Act, Regulations & Guidelines contain provisions addressing the conduct and performance of activities within the extractive industries, including requirements to submit an environmental impact assessment and management plans and, if drilling is involved, response plans.

Permits are issued by the Department of the Environment, but the petroleum aspects of this legislation are included in an ongoing revision of the regulatory framework.