Case Study of Multiple-Hydraulic-Fracture Completion in a Subsea Horizontal Well, Campos Basin

Abstract

Summary This paper provides a case history of the first hydraulic fracture on a subsea horizontal well in the Quissama formation, a low-permeability limestone reservoir in Campos basin, Brazil. The well was drilled in the direction of the expected fracture growth, thus evolving longitudinal fractures along the horizontal section. It is part of a research project to evaluate selective stimulation methods for subsea horizontal wells. Every aspect since the drilling, completion, and evaluation of the well was handled with the end in mind of hydraulically fracturing it in several stages. Hydraulically fracturing a horizontal well has become a more accepted practice in our industry. The procedures used in fracturing vertical wells must be taken into consideration when fracturing a horizontal well, to avoid refracturing work. Near-wellbore (NWB) problems are usually the main reason that fracturing work is not completed. This paper describes hydraulic-fracture treatments with detailed discussion on analysis of calibration tests, fluid-efficiency tests (FETs), and lessons learned. Results of the pumping work will be presented showing theory and how common practices played a key role for a successful application of techniques used. Laboratory tests performed with cores taken from the well itself, such as rock mechanics, proppant embedment, compaction measurements, and basic mineralogy, are presented. Production results will be presented and compared to conventional methods used on other subsea horizontal wells in Campos basin.