Subzero Hydraulic Fracturing: A Field Case Study, Lisburne Carbonate Reservoir, Prudhoe Bay Unit, North Slope, Alaska

Abstract

ABSTRACT A successful hydraulic fracture treatment was performed on a delineation well in the Lisburne naturally fractured reservoir, North Slope, Alaska during extremely severe weather conditions. The well performance information from this delineation well was of critical importance to the development and subsequent funding of the $2 billion Lisburne project. Logistical problems which developed prior to the fracture treatment required special design considerations usually taken for granted in many North American locations. Special considerations for economy, the environment and safety were integrated into a straightforward hydraulic fracture treatment performed at a wind chill temperature of −85°F (−51°F ambient). This paper discusses the fracture design and February 11, 1984 field treatment which led to the successful stimulation of the South Bay State No. 1 delineation well. Also included is a discussion of the results obtained from the subzero hydraulic fracture treatment. A better understanding of equipment performance, fluid rheology, proppant mixing, logistic limitations and human elements under severe weather conditions was gained from the treatment. In addition, this paper addresses the following cold weather concerns that arose prior to the implementation of the fracture treatment: ○ Use available equipment, successfully perform hydraulic fracture treatment. ○ Mix proppants and additives "on the fly". ○ Proper function of electronic, pneumatic and hydraulic systems as well as rubber conveyor belts. ○ Safe and proper seal of surface tubulars. ○ Rheological properties of gelled diesel. ○ Effects of the elements on human beings. ○ Pre-frac breakdown to gain more data. ○ Uncomplicated pump schedule.