The Faja Orinoco and the Alberta Oil Sands are the two largest heavy oil accumulations on Earth. The Faja Orinoco has 1.2 Tbbl BIIP (bitumen initially in-place), primarily in the Miocene Oficina Formation. The elongate W-E deposit lies on the southern edge of the Eastern Venezuelan Basin, parallel to and north of the Orinoco River – in Guárico, Monagas, and Anzoátegui States. By comparison, the Alberta Oil Sands total 1.7Tbbl BIIP, in the Cretaceous Mannville Group and underlying (undeveloped) Paleozoic subcrop along the northeast edge of the Western Canadian Sedimentary Basin.
The two deposits bear many similarities. Both occur in updip pinch outs of foreland basins atop continental shields (Faja, Guyana Shield; Alberta, Canadian Shield). In both instances, freshwater incursion biodegraded oil to bitumen (API <= 10°). Reservoirs are fluvio-estuarine channels deposited during marine transgressions. Sandstones have 30+% porosity, with multi-Darcy permeability and 80+% oil saturation. Oil migrated long distances from source rocks deeper to basin ward (Faja, Cretaceous Querecual Formation; Alberta, Mesozoic Nordegg/Exshaw Formations).
Faja Orinoco deposits were discovered in the 1930s, but deemed sub-commercial compared to other resources in-country. In the 1990s, Venezuela launched an ‘Apertura’, inviting international oil companies (IOCs) back to Venezuela after the 1975 nationalization and creation of National Oil Company (NOC) PDVSA – specifically to develop extra-heavy oil. Four joint ventures were created, operated by International Oil Companies (IOCs) partnered with PDVSA – Cerro Negro (Exxon), Hamaca (Texaco), Petrozuata (Texaco, ConocoPhillips), and Sincor (Total, Statoil). PDVSA subsidiary BITOR (Bitúmenes Orinoco) briefly exported bitumen emulsion to European power plants. Total capacity of these five projects was~750 kbopd, and they peaked in the early 2000s. Under Hugo Chavez, PDVSA asserted operatorship. Resource nationalism and CAPEX/OPEX budget cuts have reduced these projects to a fraction of capacity.
Development schemes are similar for all Join Ventures (JVs). Reservoirs are drilled with radial or parallel 1000m laterals, 10-30 wellbores from each well pad. Heavy Oil is produced by artificial lift, a combination of progressing cavity pump and diluent (gas condensate) injection at reservoir level. Merey-16 diluent+bitumen blend is piped to four coastal upgraders near Puerto La Cruz on the Caribbean coast. The ‘heavy primary’ production scheme is similar to that implemented in thinner Alberta Oil Sands. Recovery factors are low (~10%); Enhanced Oil Recovery (EOR) has been piloted, not implemented.
Alberta is an analog for heavy oil development schemes potentially applicable to the Faja Orinoco. Compared to Alberta, the Faja is deeper (600-1500m); temperatures are higher, and viscosities are lower. Faja has stacked flow units within a thicker gross interval. The Faja Orinoco produces 0.45 MMbbl/d today, compared to 3.5 MMbbl/d from the Alberta Oil Sands. Strip mining, accounting for 1.5 MMbbl/d in Alberta, is not applicable in Venezuela. Thermal EOR (tEOR) accounts for 1.6 MMbbl/d in Alberta, in two basic configurations – Steam-Assisted Gravity Drainage (SAG-D, recovery factor 60+% )and Cyclic Steam Stimulation (CSS, recovery factor 40+%). Within the Faja, basal units are more amalgamated (favors SAG-D), and upper units have lower vertical permeability (favors CSS). Three Alberta SAG-D projects, each producing 200+ kbopd, are the world’s biggest steam floods. Heavy primary production accounts for only~10% of Alberta Oil Sands production compared to 100% from Faja. Even in thinner sands, Canadian operators have successfully implemented polymer flood.
Based on industry experience in the Alberta Oil Sands, adaptations of tEOR (SAG-D, CSS), and polymer flood, appear well-suited to the Faja Orinoco. Significant potential exists for undeveloped reservoirs, as well as improving recovery factors within currently-producing leases.
U3 Explore Venezuela project team of local and international experts has collaborated on this and two other related studies published by U3 Explore. You can read more at:
- Comparison of the methods of the Enhanced Recovery of a heavy oil between the Huyapari block in Ayacucho area in Venezuela and Quifa-Rubiales field in Colombia
- Learning from production from the Alberta Oil Sands - Dependencies between Geology and Petroleum Engineering Solution
U3 Explore geologic-engineering team is available for consulting or expert boards sessions using the results of this and other two studies in applying the best fitted EOR method in the producing fields of northern South America.