Although horizontal wells may offer significant production improvement over vertical wells, it may be necessary to fracture horizontal wells to maximize their return on investment. This is especially true in the case of tight gas formations.

This paper presents a model for fractured horizontal wells operating under constant pressure conditions, which is most suitable for producing tight gas reservoirs. The created fracture may be longitudinal or transverse. In this paper we examine the factors involved in determining the optimum number of transverse fractures for both finite and infinite reservoirs. For a group of transverse fractures, the rate distribution for each fracture is presented and analyzed. The effect of uneven fracture length is briefly presented.

The performance of a longitudinal fracture is examined and compared to a fractured vertical well and to a transverse-fractured horizontal well. A comparison of longitudinal versus transverse fractures from reservoir and operational points-of-view is presented. Also included is a short discussion of field examples.

Because performance of a longitudinal fracture is almost identical to that of a fractured vertical well, the existing solutions for fractured vertical wells may be applied to longitudinal fractures with a high degree of confidence. This approximation is valid for moderate to high dimensionless conductivity. In the case of transverse fractures, the outerfractures outperform the inner fractures. However, more than two fractures are necessary to efficiently produce the reservoir for most cases. A simplified economical analysis supports this conclusion.

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