Efficient production estimation for a hydraulic fractured well considering fracture closure and proppant placement effects

Abstract

It is important to accurately estimate performances of a hydraulic fractured well, because it will be utilized to evaluate various completion parameters and furthermore to establish a future development plan. Shale gas reservoirs with fracture networks have high initial production rates but show drastic production decline as reservoirs are depleted by production. One of the reasons behind this phenomenon is an increased effective stress during production resulting in fracture closures. Gas mainly flows through hydraulic and natural fracture networks, so the fracture closures cause permeability reduction in the flow areas. In typical hydraulic fracturing operations, proppants are injected with fracturing fluid and placed in the fracture networks. Proppants play a crucial role to keep an induced hydraulic fracture open and retain a well productivity. However, only small portion of the fracture networks are filled with proppants (propped fracture) and the rest exist without proppants (unpropped fracture). Therefore, fracture closures of these regions are quite different. In this article, we have investigated to identify the combined effect of fracture closure and proppant placement on production estimation of a shale gas well. A numerical model has been developed to mimic well performances in Horn River Basin, BC, Canada. We have used pressure-dependent correlations based on experiments to consider fracture permeability alteration with changing reservoir pressure. Proppant placements are described using a fracture propagation model and this enables to classify a whole reservoir into sub regions such as propped, unpropped fracture, and matrix. By comparing with different cases, this article shows that reasonable results on gas production estimation are accomplished when considering fracture closure and proppant placement effects together.

A review of recent research and development of the effect of hydraulic fracturing on gas adsorption and desorption in coal seams

“…fine sand) with regular roundness and compressive strength, and the newly formed fractures cannot close and the opening of hydraulic fractures is retained. As a result, gas can flow throughout the fracture network, and the flow conductivity of the coal seam is correspondingly improved (Keshavarz et al., 2015; Lee et al., 2016).…”

“…Hydraulic fracturing in coal-rock mass can transform a reservoir with low permeability, low reservoir pressure, and a low gas saturation level, thereby improving the production of CBM wells. Moreover, hydraulic fracturing can also be conducted to control coal mine gas and prevent coal–gas outbursts (Li et al., 2015a, 2015b; Yan et al., 2015; Yuan et al., 2015a, 2015b).…”

Investigating the Impacts of Nonuniform Proppant Distribution and Fracture Closure on Well Performance in Shale Gas Reservoirs

“…A number of reported studies, which investigated the impacts of proppant distribution and fracture closure on the well performance in shale gas reservoirs, are summarized as follows: Sierra et al (Sierra et al, 2014) and Cipolla et al (Cipolla et al, 2009;Cipolla et al, 2010) investigated the effects of the high-conductivity arch, unpropped fracture conductivity, and proppant distribution on gas production; however, they did not consider the fracture closure. Lee et al (Lee et al, 2016) proposed the numerical model incorporating fracture closure to study the influence of proppant distribution in fracture on cumulative gas production. Liu et al(Liu et al, 2018;Liu et al, 2019) studied the effects of fracture closure and proppant distribution on water flowback and gas production by using geomechanical simulation and flow simulation separately.…”

Integrated Workflow of Geomechanics, Hydraulic Fracturing, and Reservoir Simulation for Production Estimation of a Shale Gas Reservoir

“…Lee et al [7] constructed a numerical reservoir model based on an integrated workflow for modelling an unconventional reservoir. They investigated both fracture closure and proppant placement effects.…”