Oriented Perforations - A Rock Mechanics View

Abstract

Abstract Hydraulic fracture initiation dictates the communication path between the wellbore and fracture plane. Nonplanar fracture geometries such as multiple, T-Shaped, and reoriented fractures are not advantageous and they adversely affect the potential to achieve a desired stimulation treatment. Oriented perforation can be the solution to initiate a single wide fracture in vertical and deviated wells. Also oriented perforations may be used to create stable tunnels in poorly consolidated formations thus avoiding sand failure and consequently preventing sand production. This paper presents laboratory experimental results related to oriented perforations for hydraulic fracturing. It also discusses the use of oriented perforation for sand control. Experiments were designed to investigate the effect of perforation orientation in vertical and horizontal wells on hydraulic fracturing treatment. Introduction Oriented perforation has not been widely applied in the industry due to practical difficulties involved in this process. However, more applications are becoming candidates for oriented perforation, i.e., fracturing deviated and horizontal wells, controlling sand production, and solving wellbore instability problems. The first work on the effect of perforation on hydraulic fracturing was presented by Daneshy who showed that the direction of induced hydraulic fracture is not dictated by perforation orientation. He showed that in many cases, fluid traveled from the perforation through the area between the casing and formation to initiate a fracture in the direction of maximum horizontal stress. Several authors showed that the perforation orientation in horizontal wells should be in phase with the anticipated fracture direction. Field observations on the effect of oriented perforation were reported for vertical and deviated wells. Venditto, et al. reported a field observation on a vertical well. P. 411^