Unconventional Shale Play Selective Fracturing Using Multilateral Technology

Abstract

Drilling, completing, and fracturing of unconventional formation wells in North America are now commonplace and will begin to play a role in the future of natural gas production in the international market. What is not as common is to drill, complete, and frac multiple lateral branches from a single main wellbore. Multilateral wells have been routinely drilled for a number of applications, and shale plays are a natural progression for its use. Augmenting a multilateral well with selective fracturing of each leg is as straightforward as fracing a single horizontal well.Using conventional equipment and techniques, a multilateral well (with any number of laterals) can accommodate any type of fracturing system and program with pressures up to 12,500 psi with complete isolation of the lateral junction(s). In this project, a plug-and-perf system was used to address ten plus intervals in each leg, with average stimulation pressures up to 9,000 psi.Multilateral solutions provide the means to work within a limited surface access, generating a reduced footprint while draining a much larger volume of the reservoir from a single-surface location. This poses a significant advantage when drilling in sensitive or restricted locations, populated areas, and where land issues restrict access to multiple drilling locations. Additionally, the cost and impact of large drilling pads or multiple well sites is avoided. This paper will discuss the implementation and execution of this project, the first dual-lateral well by any operator in the Granite Wash at vertical depths over 12,000 ft. This well targeted two different sections of the Granite Wash (a complex series of sands, shales, and siltstones that run from the northern Texas Panhandle into Oklahoma) from a single main wellbore, with commingled production rates doubling typical single horizontal well performance.