Historically, hydraulic fracturing has been principally applied to low permeability formations as a means of stimulating a well’s production performance. In recent years, hydraulic fracturing for formation control as well as enhanced productivity in high permeability unconsolidated formations (i.e., frac-packing) has gained broader acceptance. This paper reviews frac-pack results in the Mahogany Field, a large gas-condensate field producing from unconsolidated high permeability sands. Even though frac-packing was very successful in these applications, numerous other completion techniques such as high rate water packs and conventional gravel packing are available and still being utilized throughout the world. For a field development engineer, few guidelines are available which aid in optimizing completion decisions.

Field examples from Mahogany Field in offshore Trinidad are used to demonstrate a successful completion design selection procedure. The benefits and risks of gravel packs, high rate water packs, and frac-packing in the completion of high deliverability wells in these unconsolidated formations will be reviewed. Results of rock mechanics, fines migration, and embedment testing will be presented and coupled with a production optimization study to develop completion guidelines applied in Mahogany Field. Finally, this paper will show a direct comparison of a gravel pack completion (80 mmcfpd) and a frac-pack completion (160 mmcfpd) in offset wells from the same productive horizon. Current production performance and long term recovery predictions will be reviewed.

This paper will make the following technical contributions:

Present the results of an extensive laboratory study of rock mechanics, fines migration, and embedment testing, and show the value of such testing in making completion decisions.

Develop and present guidelines for determining the optimal completion practices in high permeability unconsolidated formations.

Show a direct comparison between a conventional cased-hole gravel pack completion and a frac-pack completion.

Present details of a successful frac-pack completion in a formation with severe fines production problems.

Keywords:
bottomhole pressure, fine migration, productivity, criteria, spe 63105, reservoir, permeability, frac-packing high-permeability sand, frac-pack completion, upstream oil & gas
Subjects:
Hydraulic Fracturing, Reservoir Fluid Dynamics, Formation Evaluation & Management, Frac and pack, Fracturing materials (fluids, proppant), Flow in porous media, Drillstem/well testing, Sand Control, Completion Operations
Copyright 2000, Society of Petroleum Engineers
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