When designing fracture treatments for high permeability formations, fracture conductivity is a primary factor in attaining maximization of completion economics. Optimum fracture design would dictate the knowledge of fracture orientation and the utilization of oriented perforation to optimally place the fracture. While in many unconsolidated formations, the contrast between horizontal stress is small or even insignificant; taking advantage of this situation often improves the efficiency and placement of a fracture.

It is generally believed that existing spiral patterns used in more conventional slurry pack completions give better radial flow performance because of the uniform perforation distribution around the wellbore. However, when a hydraulic fracture is created, the majority of flow into the wellbore is delivered through the perforations that are communicated to the fracture. This is especially true when many of the unconsolidated formations suffer a high degree of damage around the wellbore. For this reason, it is important to focus fluids injected during the completion directly to the fracture and increase the number of perforations communicating with the fracture. This paper will discuss the justification and theoretical background for a newly proposed design that develops this concept. The paper also discusses the tools and procedures necessary to achieve the stated goals.

A case history will be presented that will discuss the methods employed by an operating company in offshore Louisiana in perforating unconsolidated formations with the new system to obtain highly conductive gravel-pack fractures in deviated vertical wells. Significant to the success of the completions was the use of a high shot density perforating gun, oriented at 180-degree phasing. To facilitate the new approach, an innovative perforating gun system was also developed, and a wide perforation was designed to minimize friction.

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