Horizontal Drilling and Openhole Gravel Packing with Oil-Based Fluids-An Industry Milestone

Autor: Tamara Webb, Matthew Maharaj, Golchehreh Salamat, Taylor Green, Michael R. Wagner, Allan Jeffery Twynam, Mehmet Parlar
Rok vydání: 2006
Předmět:
Zdroj: SPE Drilling & Completion. 21:32-43
ISSN: 1930-0204
1064-6671
Popis: Summary An increasing number of horizontal wells requiring sand control are being gravel packed, particularly in deepwater and/or subsea environments in which completion reliability is paramount because of the prohibitively high cost of remediation. Tophole sections in many of these wells are being drilled with oil-based (OB) fluids, with the common practice of switching to water-based fluids when the reservoir drilling starts. In the last several years, some operators started using OB drilling fluids in the reservoir section as well and gravel packed them with water-based fluids. In some cases, these practices required running predrilled liners in OB fluids and subsequently displacing to water-based fluids before running in hole with the sandface screens and gravel packing. In other instances, screens could be run in hole with OB fluids in the wellbore, and gravel packing could be performed with water-based fluids. In both cases, the presence of reactive shales and/or water-sensitive productive zones can introduce serious concern, in the event that carrier-fluid losses occur into the formation during gravel packing. Although a base-oil or diesel can be used as a carrier fluid, low density of the base oil limits such applications to low-pressure/depleted wells. In this paper, we present a case history of the first successful application of drilling and completing in an all-oil environment, using a reversible OB reservoir-drilling fluid (RDF) (the filter cake of which reverses wettability from oil to water when exposed to an acidic fluid) and an OB gravel-packing fluid. The carrier fluid used in this application included a filter-cake cleanup solution in the aqueous internal phase of the OB carrier fluid, extending the application of simultaneous gravel-packing and cake-cleanup processes that have been successfully practiced in water-based-fluid environments to OB systems. The subject application was in a high-rate gas field located offshore Trinidad, with anticipated production rates in excess of 150 MM scf/D per well. Presented in the paper is the drilling and completion selection methodology based on extensive laboratory and yard testing, along with the details of the completion and recommendations for future applications based on lessons learned. A direct comparison of the all-oil drilling and completion process to water-based drilling and completion is also presented based on a case history from the same field.
Databáze: OpenAIRE