When horizontal wells are completed with transverse fractures, the area of intersection between the wellbore and fracture can be severely limited. These authors recognized the significance of non-Darcy flow and convergence skin and selected a high conductivity 16/20 ceramic proppant to maintain conductivity in the near-wellbore region, despite high calculated Fcd obtained with less expensive frac sand. Based on modeling, the well was designed for 4 transverse fractures. The ultimate recovery of the fractured horizontal well is estimated at 450,000 barrels of oil, 3.5 times that of a typical vertical well.
This paper presents a detailed description of the completion and fracture stimulation of a high-angle well in the Madison formation of the Williston Basin in North Dakota. The case history of the Candee 26-13 HA well is used. The completion and fracture stimulation techniques used on this well resulted in a three and a half-fold increase in the ultimate recovery of the well, in comparison to a vertical well in the same field.
The well was directionally drilled to intersect natural fractures and provide optimal conditions for hydraulic fracture stimulation. To ensure zone selectivity and isolation, the well was cased and cemented. Notching techniques were used to allow hydraulic fracture treatments to be selectively initiated along the wellbore. Matrix acidizing was an essential phase to achieve this goal.
This paper also presents a discussion of how reservoir simulators can be used to optimize the number of fractures needed to cover a given drainage area. In addition, prefracture and postfracture evaluations are discussed.
Author(s): Hazim H. Abass, Halliburton Energy Services; Peter Hagist, Pennzoil; James Harry, Choctaw II Oil and Gas, Choctaw II Oil and Gas, Ltd.; James L. Hunt, Halliburton Energy Services; Mark Shumway, Ltd.; Naz Gazi, Halliburton Energy Services
Paper Number: SPE 29443