Shallow Horizontal Drilling Meets with Very Extended Reach Drilling in the Venezuelan Faja

Abstract

Abstract Early in the 1990s, Venezuela accelerated drilling and production of the Orinoco oil belt called "La Faja." Since then, thousands of horizontal wells have been drilled. Despite the giant reserves in the highly porous and permeable sands found in the Faja, low reservoir pressure and heavy oils with reduced crude API require that reservoir exposure for production is maximized. Because of this, longer horizontal sections are being drilled and will continue to be drilled in the Faja. Drilling of the Faja started in reservoirs of true vertical depths (TVD) from 2, 500 ft to 4, 000 ft; however, as the development of the Orinoco belt has moved towards the south, reservoirs in the last 5 years have been drilled at TVDs from 1, 500 ft to 2, 500 ft. Further development, in the last 2 years, of the southern Faja has required drilling reservoirs at TVDs from 1, 200 ft to 1, 500 ft. Drilling horizontal wells at these shallow TVDs requires adequate planning and execution because of the inherent risks of high dogleg severity, cyclic stress of bottomhole components, high torque and drag, poor hole cleaning, inadequate weight-on-bit transfer, pipe swaps, wiper trips, and stuck pipe events. To maximize reservoir exposure, recent advances in extending horizontal lengths of these shallow wells have also been achieved. A few wells drilled in south Faja in 2013 fit the very extended reach drilling classification as defined by the oil industry because of their 1:4 stepout ratio, the ratio of true vertical depth versus horizontal displacement. Along with the evolution of shallow horizontal and extended reach drilling, advances in surface pads and trajectory design, bottomhole assemblies (BHAs), drilling practices, directional drilling tools, and advanced geosteering techniques have allowed drilling extended reach wells of longer total depth with reduced nonproductive time, enabling increasing oil production in the Faja. Experience in the execution of shallow horizontal ERD wells has led to the consolidation of lessons learned and capture of best practices which will be key to improving drilling along the extensive southern area of the Faja, where reservoirs even shallower than 1, 100 TVD are found.