Project Profile
Location: Putumayo basin, near the Ecuadorian border, southern Colombia
Reserves: 700 million bbl of oil-in-place
Production: 21,000 bfpd with an oil rate of 6700 bfpd
Area: 43 sq km
Drilling Depth: 1,500 – 7,500 feet
The Orito field located beside the town of Putumayo basin in the South of Colombia, near the Ecuadorian border has been in production since 1967 and is operated by Ecopetrol (originally discovered and exploited by Texaco).
Petrominerales signed an Incremental Production Contract agreement in April 2001 to participate in increasing production from the field. Under the terms of the agreement Petrominerales invest 100% of any development activity in return for a portion of the value of the incremental production. Since commencing operations in the Orito field Petrominerales have worked over 47 wells and drilled 28 new wells. An active drilling program is being pursued resulting in approximately 1 new well per month. As part of the standard completion procedure new wells are hydraulically fractured, as this has been shown to increase well inflow performance significantly.
Geology
The field originally contained more than 1 billion bbl of oil-in-place, in three primary reservoirs. The most significant is the Cretaceous Caballos formation, a complex series of fluvial/ deltaic and marginal marine sands that originally contained more than 700 million bbl of oil-inplace and is still the main productive interval. The Caballos zone, alone, has produced 191 million bbl since the field was discovered in 1963. The Orito reservoir is a multi layered reservoir with three production intervals: Pepino from depths of 1,500- 2,500 ft, Villeta from 5,000 – 6,500 ft; and the Caballos at 6,500 – 7,500ft. The reservoirs are depleted and pressures are below the original bubble point pressure. The wells can exhibit a number of challenges for production of fluids using artificial lift including: scale, solids production high, GOR, early high water production and also very high CO2 (80%).
Typically, Petrominerales target the Caballos formation as the primary zone of interest. While potential for the field is high, increasing the production rate from the field has proven to be difficult due to: the highly heterogeneous nature of the formation making picking of new well locations difficult; rapidly increasing watercut, challenges with uptime of artificial lift equipment and serious delays in undertaking optimisation work.
Operators:
Petrominerales: Operator with 100% interest