Abstract

Although hydraulic fracturing has been a widely used stimulation technique; very few hydraulic fracturing treatments have been performed in low-permeability formation types since traditional fracturing treatments have not provided significant benefit. Now, however, new technological advances in fracture extension, proppant design, and fracturing fluids have enabled hydraulic fracturing to be extended beyond the original applications so that low-permeability formations can also benefit from their application. These new techniques can be employed in both high permeability as well as poorly consolidated formations and have significantly improved the chance of success when applied.

Conventional completion techniques had traditionally provided minimal or no productivity from wells completed in low to moderate-permeability formation types. However, application of the state-of-the-art hydraulic methodology now available has proven that wells in these formations can be produced successfully and economically. This paper will discuss recent cases of successful use of hydraulic fracturing techniques that have shown that fracturing can improve productivity in non-traditional applications.

The fracturing process used in these fracturing campaigns was recently co-developed by the service company and the operator. The discussion in the paper will outline the various processes employed in the candidate selection, pre-fracture testing, fracture-design optimization, and post-fracture evaluation. The methodology is outlined, and fracturing results from the various wells are discussed. Pre-fracturing tests allowed the servicing company to optimize the fracturing treatment, and the post-fracturing evaluation provided a high degree of confidence in the process. In seven out of eight fracturing treatments, the planned fracture parameters were within a few percentage points of the calculated parameters.

Introduction

Hydraulic fracturing can be defined as a process in which fluid pressure is applied to the exposed reservoir rock until failure and breakdown of the formation occur. Then, sustained application of the fluid pressure extends the fracture outward from the point of failure. The techniques achieve the objectives by creating artificial channels that connect the permeable small sand strikes and increase the capability of the reservoir rock to conduct fluid into the wellbore.

Because of the low-permeability formation types in Egypt and the fact that in this formation type, the traditional fracturing treatments had not been beneficial, very few hydraulic fracturing treatments have been performed in Egypt during the last thirty years. The Abu Roash and Upper Baharyia formations, operated by Khalda, have been classified as low- to moderate-permeability formations because of the lithology variation in the vertical and lateral direction of imbedded sandstone and shale layers along with other minerals. Conventional completion techniques had provided minimal or no productivity from several wells completed in these formations. However, since state-of-theart hydraulic fracturing methodology had been allowing wells in these types of formations to be produced successfully and economically in other areas, the operator and service company decided to select several candidate wells on which to try the new fracturing procedures.

Eight successful hydraulic fracturing procedures have now been performed in the Abu Roash and Upper Baharyia formations. The wells were located in the Sharouk, Kahraman, Kenz, and Nader fields in the western desert of Egypt.

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