Response of Wells Producing Layered Reservoirs: Unequal Fracture Length

Abstract

The response of fractured wells producing noncommunicating layered reservoirs is the focus of this work. The conductivity of the fracture is assumed to be finite. The fracture length is assumed to vary from layer to layer. Two modes of production-constant wellbore pressure and constant rate-are considered.In the first part, the fractures are assumed to communicate only at the wellbore. The results given in this section are intended to provide engineers with analytical capabilities to examine responses in wells where the layers that have been stimulated are separated by considerable distances. Procedures to interpret the results of pressure buildup and/or production tests (draw down responses) in terms of layer properties are presented. Criteria to ensure maximum productivity are specified. The second part examines well responses when the fractures are in communication at points other than the wellbore. All other things being identical, we show that communication between fractures increases productivity.

Practical Solutions for Pressure-Transient Responses of Fractured Horizontal Wells in Unconventional Shale Reservoirs

“…47, p ws is the bottomhole shut-in pressure and p wf,s is the bottomhole pressure at the instant of shut-in. Chen and Raghavan (1997) and Raghavan et al (1997) developed analytical pressure-transient solutions for multiple-fractured horizontal wells in homogeneous reservoirs by using the ideas of Bennett et al (1985) and Camacho-V. et al (1987), who developed solutions for fractured vertical wells in layered reservoirs. For a homogeneous reservoir, substituting f(s) = 1 and u = s in Eq.…”

Effect of Pressure in a Well With a Vertical Fracture With Variable Conductivity and Skin Fracture

“…Other solutions have been derived for the case of flow at constant pressure 7 , Rodriguez et al 8 shows the behavior of a well with a partially penetrating hydraulic fracture. Bennett 9,10 showed a multi-layer solution, and Camacho et al 11 presented a multi-layer model for different half-fracture lengths. Cinco Ley and Meng 12 derived a solution for the case of hydraulic fractured wells in double porosity formations.…”

Approximate Solutions for Fractured Wells Producing Layered Reservoirs

“…66 or its counterpart for a singlelayer system, Eq. 67, was first derived by Camacho-V. 4 Again we see that the principal difference between the commingled reservoir solution and the single-layer response is the appearance of the term ReD. Intuitively speaking, we would expect the linear flow period (Eq.…”

“…They provide the only means to verify the accuracy of finite-difference models for solutions when no solutions are available or when the solutions presented in the literature are not in agreement. 4 …”