Petroleos de Venezuela, S.A. (PDVSA) Petrocedeno has encountered challenges in achieving higher production rates and maximizing extra-heavy oil recovery from complex reservoirs in the Junin block of the Orinoco oil belt of Venezuela. These complex reservoirs are located in heterolytic deltaic depositional environments, with heterolitic thicknesses ranging from 10 to 20 ft. This block produces 150,000 B/D from more than 700 horizontal wells. Most of these wells were drilled in relatively homogeneous sands with good thickness; however, large extra-heavy oil reserves are trapped in a more geologically and operationally complex deltaic reservoir sand. Horizontal wells in this area show poor production results.
For these reservoirs, the geosteering technique with azimuthal deep resistivity technology was proposed to maximize oil recovery by positioning the wellbore in a better pay-zone; advanced drainage multilateral architecture was proposed to improve production rates by increasing reservoir exposure. Multilateral technology has been used successfully in the area. Sand problems, observed in some multilateral wells, were solved by using a junction support tool to provide mechanical and hydraulic integrity at the junction area. A real-time geosteering technique enabled a flawless wellbore placement within this reservoir with challenging stratigraphy and complex sedimentological environment in which more than 60 wells have been drilled with azimuthal deep resistivity tools.
The well YC-36 well plan included drilling two laterals with the geosteering technique, which would improve the production rate to an estimated 343 B/D. After installing a multilateral level IV junction and positioning YC-36 100% in the net oil sand, the reported production increased to 650 B/D for an increase of approximately 300%, as compared to an average single well production from the block. This paper describes the combined application of multilateral and geosteering technologies in the YC-36 well and details about the results of the application.