Anyue Field (China) – New to DAKS. A giant new discovery (2011) in the Sichuan Basin with production beginning in 2015. This field has a GIIP of 44.6 TCF with a recovery factor of 54%, with majority of the GIIP in the Sinian (Precambrian) Dengying 4 reservoir (47% of GIIP) and Lower Cambrian Longwangmiao Formation reservoir (35% GIIP). The Longwangmiao reservoir is a fractured carbonate reservoir while the Dengying 4 reservoir is a fractured and karstic reservoir. Commercial production started in late 2015 from Longwangmiao followed in 2018 by the Dengying 4 reservoir. Acid-fracturing is commonly applied to both reservoirs while managed pressure drilling is essential for the Dengying 4 karstic reservoir. Cumulative production had reached 3.7 TCF by end-2022, ~60% of which is from the Longwangmiao reservoir.
Clair Field (UK) – This report has been recently updated with a wealth of new data. The field came onstream in 2005 and has a STOIIP of 7 BBO. It is the largest producing fractured reservoir in the UK. Oil with a gas cap is trapped in a regional horst within tilted fault-blocks which are being developed in phases. Two phases (Core/Graben/Horst and Clair Ridge) are currently onstream with phase 2 coming online in 2018. The two phases have a combined STOIIP of ~2.9 BBO and EUR of 940 MMBO. The Lower Clair reservoir consists of fractured Devonian fluvial and aeolian red beds. In 2016 a five-well drilling campaign led to a 70% production increase. Phase 2 development included low-salinity water injection. Further development potential exists within the planned phase 3 (Clair South) and the Greater Clair areas.
El Corcobo Norte Field (Argentina) – Onstream since 2006, this field has a STOIIP of 417 MMBO, which is contained in the Lower Cretaceous Lower Centenario reservoir. The unconsolidated, tide-dominated deltaic sandstone has an average porosity of 30% and permeability of 1400 mD. Heavy oil (18.5 °API) is trapped stratigraphically by truncation, lateral depositional pinch-out, and cementation. The reservoir lacks significant natural drive and production was mostly achieved by waterflood. Severe water channeling occurred but was mitigated by well remediations. Polymer flood was implemented at a partial scale and was successful. An ultimate recovery factor of 35% is expected.
Palogrande-Cebu Field (Colombia) – Onstream since 1980, the field has a STOIIP of 222 MMBO. An 1150 ft oil column is trapped at 5600 ft TVD by a faulted thrust anticline in the Upper Cretaceous Monserrate reservoir. Heavy oil (19 °API) has been produced from beach and shoreface sandstones, which have an average permeability of 47 mD and porosity of 18%. Production was by solution-gas drive added by continuous water injection. Polymer flooding was tested and proved successful. Hydraulic fracturing, artificial lift, and conformance control helped improve recovery. An ultimate recovery factor of 30.2% is expected.
Suban Field (Indonesia) – Ne to DAKS. The field was discovered in 1972 and production started in 2002. It has a GIIP of 7 TCF with a recovery factor of 81%. Gas is found in pre-Tertiary Basement and the overlying Oligo-Miocene sediments in three fault blocks. All the reservoirs are extensively fractured and are in widespread communication. Production by natural energy increased rapidly and entered a prolonged plateau from 2009. As of 2018, the field had reached a cumulative production of 3.5 TCF.
Val D’Agri Field (Italy) – New to DAKS. This field came onstream in 1993 and contains an EUR of 939 MMBO with a recovery factor of 21%. A large 1200 m oil column is contained in fractured and karstified Apulian platform carbonates within a thrusted duplex with three culminations known as Monti Alpi, Monte Enoc and Cerro Falcone. These were originally thought to be separate fields but later proved to be a single pool. The reservoir is extremely heterogeneous with faults and fracture swarms providing the main storage and flow conduits since the reservoir has low matrix porosity of only 1-2% and permeabilities of only 0.1-10 mD. Production is through clustered horizontal, multilateral and extended-reach wells with acidization and injection of solvents to combat asphaltene deposition. Two expansion projects are currently in the planning stages.