Hydraulic Fracturing Treatment Optimization for Low Permeability Reservoirs Based on Unified Fracture Design

Abstract

Hydraulic fracturing optimization is very important for low permeability reservoir stimulation and development. This paper couples the fracturing treatment optimization with fracture geometry optimization in order to maximize the dimensionless productivity index. The optimal fracture dimensions and optimal dimensionless fracture conductivity, given a certain mass or volume of proppant, can be determined by Unified Fracture Design (UFD) method. When solving the optimal propped fracture length and width, the volume and permeability of the propped fracture should be determined first. However, they vary according to the proppant concentration in the fracture and cannot be obtained in advance. This paper proposes an iterative method to obtain the volume and permeability of propped fractures according to a desired proppant concentration. By introducing the desired proppant concentration, this paper proposes a rapid semi-analytical fracture propagation model, which can optimize fracture treatment parameters such as pad fluid volume, injection rate, fluid rheological parameters, and proppant pumping schedule. This is achieved via an interval search method so as to satisfy the optimal fracture conductivity and dimensions. Case study validation is conducted to demonstrate that this method can obtain optimal solutions under various constraints in order to meet different treatment conditions.

Experimental and numerical investigations of proppant pack effect on fracture conductivity of channel fracturing

“…With the continuous development of unconventional oil and gas reservoirs, hydraulic fracturing has been widely applied in the industry for the enhancement of hydrocarbon recovery 1,2 . Proppants are pumped into and evenly distributed within the fractures in order to resist the closure pressure after pumping, generating highly conductive flow paths for the hydrocarbon.…”

Permeability enhancement mechanism of sand‐carrying hydraulic fracturing in deep mining: A case study of uncovering coal in cross‐cut

“…In addition, for issue of coal and gas outburst may be triggered by coal recovering at rock crosscut area. 32,33 In-depth research is hence needed to deal with the high in situ stress and to further increase the permeability enhancement effect in hydraulic fracturing (HF) process in deep coal mining. Feng et al 23 developed a fixed-point hydraulic fracturing method for coal seam rockburst prevention, and they found that resistance increasing and energy releasing are the two main roles of hydraulic fracturing in order to prevent rockburst.…”

“…In this fashion, stress-sensitive effect would cause many problems in hydraulic fracturing such as high initial pressure and fracture closure. 32,33 In-depth research is hence needed to deal with the high in situ stress and to further increase the permeability enhancement effect in hydraulic fracturing (HF) process in deep coal mining.…”

An Analytical Model for Capturing the Decline of Fracture Conductivity in the Tuscaloosa Marine Shale Trend from Production Data

“…Hydraulic fracture conductivity plays an essential role in well performance [19][20][21][22][23][24]. It can decline significantly during production owing to proppant embedment and blockage of debris [25,26].…”