Fracturing Fluid Leakoff and Damage Mechanisms in Coalbed Methane Reservoirs

1993 ◽  
Author(s):  
M.W. Conway ◽  
G.S. Penny ◽  
R.A. Schraufnagel
Keyword(s):  
Coalbed Methane ◽  
Fracturing Fluid ◽  
Damage Mechanisms

Research on Nano-Emulsion Relieving Coal Seam Water Block Damage

2021 ◽  
Author(s):  
Wei Sun ◽  
LongHao Zhao ◽  
Qian Wang ◽  
Yanchi Liu ◽  
Weiping Zhu ◽  
...  
Keyword(s):  
Coal Seam ◽  
Coalbed Methane ◽  
Mixed Micelles ◽  
Polymer Adsorption ◽  
Coal Seams ◽  
Fracturing Fluid ◽  
Flow Experiment ◽  
Nano Emulsion ◽  
Water Block ◽  
Lock In

Abstract Hydraulic fracturing is the most effective reservoirstimulation techniques in the coalbed methane. However, the polymer in the fracturing fluid has a strong effect on the surface of the coal, causing the water lock damage as high as 70% to 90%. It is important to develop an efficient method for releasing coal seam water lock. In this paper, adsorption experiment, SEM, particle size experiment, core flow experiment, wettability and surface tension experiment are used to study the cause of coal seam water lock damage during fracturing and the effect of nano-emulsion on releasing water lock damage in coal seams. Experimental results show that after coal fracturing, the adsorption amount of polymer on the surface of coal is 14.81 mg/g. The large amount of hydrophilic polymer adsorption causes the pore radius of the coal to narrow. And the surface wettability changes from weak hydrophilic to strong hydrophilic, which increase the water lock damage. Compared with conventional slick water, fracturing fluid, the composite of nano-emulsion and fracturing fluid forms mixed micelles, which reduces the polymer adsorption capacity from 14.81 mg/g to 7.42 mg/g. After scanning by electron microscope, it is observed that the surface roughness of the rock sample is restored; The size of the nano-emulsion is about 10nm, and the very small volume can act deep in the pores of the coal seam; After using nano-emulsion, the gas/water interfacial tension is reduced by 45.1mN/m, and the wettability of coal is improved from hydrophilic to neutral, which reduces the capillary pressure in the pores of the coal and reduces the breakthrough pressure of coalbed methane by 11.1KPa; The water lock release rate is as high as 53.09%. The Nano-emulsion is an ideal choice to remove water lock damage.

The Main Problems Existing in the Exploitation of Coalbed Methane

2013 ◽  
Vol 868 ◽  
pp. 589-592
Author(s):  
Cheng Xiu Zhang ◽  
Xiao Hong Ma ◽  
Tao Wang ◽  
Qiu Hui Zhan
Keyword(s):  
Coalbed Methane ◽  
Gas Flow ◽  
Damage Mechanism ◽  
Practical Significance ◽  
Fracturing Fluid ◽  
Selection Of

Coalbed methane is one of the important unconventional energy, due to its characteristics determined there must be taken effective fracturing modification measure to get industrial gas flow, this paper analyzes the damage mechanism of fracturing fluid, the selection of additives in fracturing fluid and the methods of enhancing coalbed methane, and puts forward some corresponding suggestions to improve the recovery of CBM wells supporting a certain practical significance.

scholarly journals Experimental Study on the Damage of Artificial Fracture Permeability in Coal during the Flow Back of Guar-Based Fracturing Fluid

Geofluids ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-13 ◽  
Author(s):  
Shenggui Liu ◽  
Jinkuang Huang ◽  
Songlei Tang ◽  
Shixiong Shi ◽  
Xuan Wu ◽  
...  
Keyword(s):  
Coalbed Methane ◽  
Fracture Permeability ◽  
High Concentration ◽  
Fracturing Fluid ◽  
Irreversible Damage ◽  
Damage Degree ◽  
Damage Rate ◽  
Fluid Concentration ◽  
Artificial Fracture ◽  
Coal Reservoir

After the completion of fracturing operation in coalbed methane (CBM), the fracturing fluid needs to flow back to the ground in time to reduce the damage to the coal reservoir. The damage of guar-based fracturing fluid to the coal reservoir has an adverse effect on the fracturing stimulation. A series of flow experiments were carried out with the unconventional natural gas reservoir damage evaluation equipment. This paper investigates the evolution of fracture permeability in coal samples during the process of hydroxypropyl guar (HPG) fracturing fluid flow back. The experimental results show that the fracturing fluid concentration, proppant type, proppant particle size, and proppant concentration all affect fracture permeability. The high concentration of fracturing fluid caused irreversible damage to fracture permeability of coal samples. With the increase of fracturing fluid concentration, the permeability damage rate increased from 65.31% to 84.57%, and the damage degree was strong. KCL brine flushing can only decrease the damage rate of coal sample fracture permeability within a certain range. The proppant embedment and the generation of pulverized coal exacerbated the damage of fracture permeability. The research results can be beneficial for optimizing the type and performance of fracturing fluid for hydraulic fracturing in CBM reservoir.

A Study on Gel Fracturing Fluid for Coalbed Methane at Low Temperatures

2011 ◽  
Vol 34 (1) ◽  
pp. 82-89 ◽  
Author(s):  
C. Dai ◽  
Q. You ◽  
H. Zhao ◽  
B. Guan ◽  
X. Wang ◽  
...  
Keyword(s):  
Low Temperatures ◽  
Coalbed Methane ◽  
Fracturing Fluid

Impact of surfactant in fracturing fluid on the adsorption–desorption processes of coalbed methane

2015 ◽  
Vol 26 ◽  
pp. 35-41 ◽  
Author(s):  
Qing You ◽  
Chenyu Wang ◽  
Qinfang Ding ◽  
Guang Zhao ◽  
Jichao Fang ◽  
...  
Keyword(s):  
Coalbed Methane ◽  
Fracturing Fluid ◽  
Adsorption Desorption

Impact of fracturing fluid on multi-scale mass transport in coalbed methane reservoirs

2016 ◽  
Vol 154-155 ◽  
pp. 123-135 ◽  
Author(s):  
Yili Kang ◽  
Fansheng Huang ◽  
Lijun You ◽  
Xiangchen Li ◽  
Bo Gao
Keyword(s):  
Mass Transport ◽  
Coalbed Methane ◽  
Fracturing Fluid ◽  
Multi Scale
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