3D Acid Fracturing Simulation and Application in the Upper Sinian Dengying Fm Gas Reservoirs in China

2019 ◽  
Author(s):  
Heng Xue ◽  
Zuxi Huang ◽  
Fei Liu ◽  
Pingli Liu ◽  
Hehua Wang ◽  
...  
Keyword(s):  
Gas Reservoirs ◽  
Acid Fracturing ◽  
Upper Sinian

3D Acid Fracturing Simulation and Application in the Upper Sinian Dengying Fm Gas Reservoirs in China

2019 ◽  
Author(s):  
Heng Xue ◽  
Zuxi Huang ◽  
Fei Liu ◽  
Pingli Liu ◽  
Hehua Wang ◽  
...  
Keyword(s):  
Gas Reservoirs ◽  
Acid Fracturing ◽  
Upper Sinian

scholarly journals Pre-acid system for improving the hydraulic fracturing effect in low-permeability tight gas reservoir

2021 ◽  
Vol 11 (4) ◽  
pp. 1761-1780
Author(s):  
Nianyin Li ◽  
Fei Chen ◽  
Jiajie Yu ◽  
Peihong Han ◽  
Jia Kang
Keyword(s):  
Hydraulic Fracturing ◽  
Filter Cake ◽  
Low Permeability ◽  
Tight Gas ◽  
Acid System ◽  
Fracturing Fluid ◽  
Gas Reservoirs ◽  
Tight Gas Reservoirs ◽  
Acid Fracturing ◽  
Performance Requirements

AbstractHydraulic fracturing is an important technical means to improve the development effect of low-permeability oil and gas reservoirs. However, for low pressure, low-permeability, tight, and high-clay sandstone gas reservoirs, conventional propped fracturing can cause serious damage to the reservoir and restrict the fracturing effect. The pre-acid fracturing technology combines acid treatment technology with sand-fracturing technology. A pre-acid system that meets special performance requirements is injected before fracturing. The pre-acid reduces the formation fracture pressure and removes clay damage. During acid flowback, the fracturing fluid is promoted to break the gel, dissolve the fracturing fluid residue and polymer filter cake, clean the supporting cracks, and effectively improve the fracturing effect. This study analyzes the process principle and technical advantages of the pre-acid fracturing technology based on the laboratory evaluation of the fracturing damage mechanism of low-permeability tight gas reservoirs. To meet the performance requirements of low-permeability tight gas reservoirs and pre-acid fracturing technology, a set of polyhydrogen acid system with long-lasting slow reactivity, low damage, and low corrosion was developed and used as the pre-fracturing acid. The acid system is mainly composed of the main agent SA601 and the auxiliary agent SA701. Then, on the basis of laboratory experiments, this acid system is used as the fracturing pre-acid to evaluate the fracturing improvement effect. The results show that the fracturing fluid system can better dissolve the fracturing fluid filter cake and remove the fracturing fluid damage.

A New Leakoff Analysis Approach for Acid Fracturing in Naturally Fractured Carbonate Gas Reservoirs

2019 ◽  
Vol 37 (1) ◽  
pp. 139-147
Author(s):  
Linjing Xu ◽  
Guoyong Wang ◽  
Tianyu Liu ◽  
Naizhen Liu ◽  
Shicheng Zhang ◽  
...  
Keyword(s):  
Analysis Approach ◽  
Gas Reservoirs ◽  
Acid Fracturing ◽  
Naturally Fractured ◽  
Fractured Carbonate

Acid Leakoff Mechanism in Acid Fracturing of Naturally Fractured Carbonate Gas Reservoirs

2013 ◽  
Vol 868 ◽  
pp. 682-685 ◽  
Author(s):  
Lin Jing Xu ◽  
Shi Cheng Zhang ◽  
Jian Ye Mou
Keyword(s):  
Fluid Loss ◽  
Natural Fractures ◽  
Gas Reservoirs ◽  
Gas Reservoir ◽  
Acid Rock ◽  
Acid Fracturing ◽  
Naturally Fractured ◽  
Fractured Carbonate ◽  
Acid Leakoff ◽  
Fractured Carbonates

In acid fracturing, excessive acid leakoff is thought to be the main reason that limits fracture propagation and live acid penetration distance, so its very important to do research about acid leak-off on naturally fractured carbonates. we developed a new model in this paper to simulate acid leakoff into a naturally fractured carbonates gas reservoir during acid fracturing. Our model incorporates the acid-rock reaction on the fractured surfaces. Given the information of the Puguang gas reservoir, the model predicts acid filtration and leakoff rate over time. In this study, we found that acid leak-off mechanism in naturally fractured carbonates is much different from that in reservoirs without natural fractures. The leakoff volume is several times of nonreactive acid. Since the acid widened natural fractures, leakoff velocity increase with time firstly , then decrease. While the leakoff velocity of the nonreactive fluid decrease sustained. We also analyze other sensitivity parameters of the acid leakoff. In this model, we explain the acid leakoff mechanism in naturally fractured carbonates, and provide a more accurate calculating of fluid loss.

Acid Fracturing Tight Gas Carbonates Reservoirs Using CO2 to Assist Stimulation Fluids: An Alternative to Less Water Consumption while Maintaining Productivity

2015 ◽  
Author(s):  
Mauricio Sanchez ◽  
Justin Tate Abel ◽  
Muhammad Idris ◽  
Eduardo Soriano ◽  
Alfredo Lopez ◽  
...  
Keyword(s):  
Water Consumption ◽  
Physical And Mechanical Properties ◽  
Point Of View ◽  
Tight Gas ◽  
Gas Reservoirs ◽  
Tight Sandstone ◽  
Acid Fracturing ◽  
Fracturing Fluids ◽  
Tight Carbonate ◽  
Carbon Dioxide Co2

Abstract Conventional hydraulic fracture stimulation techniques have been widely used to enhance production from tight gas reservoirs. Since the initial use of this method to increase production rates, the industry has witnessed continued advancement in terms of fracturing theory, fluids, and techniques. The use of carbon dioxide (CO2) since the early 1960s has continued to be a significant part of these advances. CO2 has been used for many years as an energy source to aid fluid recovery of well stimulation fluids. This technology predominantly has been used to stimulate tight sandstone reservoirs. There are very limited applications for low permeable tight carbonate reservoirs because of complexities associated with the physical and mechanical properties of carbonate rocks and its interaction with fracturing fluid. Nevertheless, the advantages of using assisted CO2 stimulation fluids as the elimination of potential formation damage normally associated with fracturing fluids and very rapid cleanup are still present. This paper outlines one of the first acid fracturing jobs assisted with CO2 conducted on a tight gas well reservoir in Saudi Arabia. It describes in a simple manner the screening methodology and key parameters considered during selection of a well candidate and the design process, which was based on petrophysical, mechanical, and chemistry properties of the formation and the respective interaction with treatment fluids. Moreover, primary operational procedures and guidelines are discussed, highlighting a safety risk assessment point of view. Implementing this technique in a more generalized manner in the field can help save considerable operational time and costs. CO2 used to energized fracturing fluids can increase the productivity of the well while using less water and less acid than conventional acid fracturing, which is of primary importance in such a harsh environment, requiring less water consumption.

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