Hydraulic Fracturing- A method to enhance the permeabilty of the reservoir

hydraulic fracturing is completely and easily defined in this presentation.

1. Subject: Unconventional Reservoir MEHRAN UNIVERSITY OF ENGINEERING AND TECHNOLOGY, JAMSHORO INSTITUTE OF PETROLEUM AND NATURAL GAS ENGINEERING PRESENTATION TOPIC HYDRAULIC FRACTURING PRESENTED BY: Zahid Hussain 20PG009 Ghulam Hussain 20PG021 Ayaz Hussain 20PG051 Abdul Jaleel 20PG103 Saqib Iqbal 20PG032 Muhammad Bilal 20PG030

2. HYDRAULIC FRACTURING Introduction Hydraulic fracturing, commonly known as fracking, has emerged as a pivotal technology in the energy sector over the past few decades. This technique involves the injection of pressurized fluids into subsurface rock formations to create fractures, facilitating the extraction of oil and natural gas. While it has unlocked vast energy reserves, hydraulic fracturing is a subject of ongoing debate due to its environmental and societal implications.

3. HYDRAULIC FRACTURING Introduction Hydraulic fracturing, or fracking, is a well-stimulation technique used to extract oil and natural gas from deep underground reservoirs. It involves injecting a high-pressure fluid mixture, typically consisting of water, sand, and chemicals, into a wellbore to create fractures in the surrounding rock formations. These fractures allow the hydrocarbons to flow more freely and be collected at the surface.

4. The Process of Hydraulic Fracturing Pre-Fracturing Preparation Before the actual fracturing process begins, geological surveys are conducted to identify suitable reservoirs. A wellbore is drilled vertically and then horizontally into the target formation. Drilling The wellbore is extended horizontally into the rock formation, allowing for increased contact with the hydrocarbon reservoir. Steel casing and cement are used to secure the well.

5. The Process of Hydraulic Fracturing Fracturing Fluid Injection A mixture of water, sand (proppants), and chemical additives is injected into the well at high pressure. The fluid creates fractures in the rock, and the proppants hold these fractures open, allowing for the flow of hydrocarbons. Fracture Propagation As the fluid pressure increases, fractures propagate through the rock, extending the reservoir's connectivity to the wellbore.

6. The Process of Hydraulic Fracturing

7. Stages of fracking 1. Spearhead stage : This initial stage is also referred to as an acid or pre-pad stage. It involves injecting a mix of water with diluted acid, such as hydrochloric acid. This serves to clear debris from the wellbore, providing a clear pathway for fracture fluids to access the formation. The acid reacts with minerals in the rock, creating starting points for fracture development. 2. Pad stage : The generation of the fractures takes place by injecting the pad, a viscous fluid, but without proppants, to break the rock formation and initiate the hydraulic fracturing of the target area.

8. Stages of fracking 3 . Proppant stage: After the fractures develop, a proppant must be injected to keep them open. When the fracture closes, the proppant is locked in place and creates a large flow area and a conductive pathway for hydrocarbons to flow into the wellbore. Viscous fluids are used to transport, suspend, and allow the proppant to be trapped inside the fracture. 4 . Flush stage : The job ends eventually with a flush stage, in which flush fluids and other clean-up agents are applied. A volume of fresh water is pumped down the wellbore to flush out any excess proppant that may be present in the wellbore.

9. Components of fracking fluid Fracking fluid is made up of many different recipes, according to the preferences of the driller and the characteristics of the rock that is being fractured. Nowadays, most fracking fluids are water-based. Aqueous fluids are economical and, if used with chemical additives, can provide the required range of physical properties. Additives for fracking fluids serve three purposes, namely: They enhance fracture creation; They enable proppant to be carried into the fractures; and They minimize damage to the rock formation.

10. Components of fracking fluid Although different compositions of fracking fluid are used for the different stages of fracking, a typical composition of such a fluid is shown in Figure

11. What are Proppants? Hydraulic fracturing creates fissures in the rock, but when the pressure of the fracking fluid is reduced the newly created fissures and cracks will close again. Proppants are introduced into the fracking fluid to penetrate and keep the fractures open, thereby forming conductive channels within the rock formation through which hydrocarbons can flow. A proppant is a hard and solid material, typically sand, small-diameter ceramic materials, or sintered bauxites. Sand has a relatively low strength, which can be improved by resin coating.

12. What are Proppants? The shape and size of the proppant are important because shape and size influence the final permeability through the fracture. For the fracking fluid to be able to carry the proppant into the fractures, the fluid must be viscous enough to prevent the proppant from settling out before it has been carried to the desired position.

13. Parameters Affecting Hydraulic Fracturing 1. Geological Factors The geological characteristics of the reservoir, including rock type, porosity, and permeability, play a crucial role in determining the success of hydraulic fracturing. 2. Fluid Properties The composition of the fracturing fluid, including its viscosity, chemical additives, and temperature, affects the fracturing process.

14. Parameters Affecting Hydraulic Fracturing 3. Proppants The type and size of proppants used influence the ability of fractures to remain open, impacting resource recovery. 4. Injection Pressure The pressure at which fluids are injected into the wellbore is a critical parameter, affecting fracture initiation and propagation. 5. Wellbore Design The design of the wellbore, including its length, casing, and cementing, is crucial for ensuring the integrity of the well.

15. Advantages of Hydraulic Fracturing 1. Increased Energy Production Fracking has substantially increased domestic energy production, reducing reliance on imports and enhancing energy security. 2. Job Creation The industry has created jobs across various sectors, from drilling and extraction to support services and manufacturing. 3. Reduction in Greenhouse Gas Emissions The transition from coal to natural gas, made possible by fracking, has led to reduced greenhouse gas emissions, contributing to climate change mitigation efforts.

16. Disadvantages of Hydraulic Fracturing 1. Environmental Concerns Environmental concerns associated with hydraulic fracturing include the potential for groundwater contamination due to the migration of fluids and chemicals, habitat disruption caused by infrastructure development, and the release of methane, a potent greenhouse gas, during drilling and extraction. 2. Water Usage and Contamination The substantial water requirements for hydraulic fracturing can strain local water resources, and inadequate wastewater management can lead to the contamination of surface and groundwater.

17. Disadvantages of Hydraulic Fracturing 3. Induced Seismicity The injection of fluids into the earth can induce seismic activity in some regions, leading to concerns about the potential for earthquakes associated with hydraulic fracturing operations. 4. Health Impacts There have been reports of health issues in communities located near hydraulic fracturing sites, with concerns related to air quality, exposure to chemicals, and potential health impacts that require further research and investigation.

18. Applications of Hydraulic Fracturing In general, hydraulic fracture treatments are used to increase the productivity index of a producing well. There are many applications for hydraulic fracturing. Hydraulic fracturing can: Increase the flow rate of oil and/or gas from low-permeability reservoirs Increase the flow rate of oil and/or gas from wells that have been damaged Connect the natural fractures in a formation to the wellbore Increase the area of drainage or the amount of formation in contact with the wellbore

19. Fracturing Oil wells vs Gas wells The basic principles of hydraulic fracturing are similar for both gas and oil wells, there can be some differences in the specific methods and techniques used, primarily due to variations in reservoir characteristics and the end goals of the operation. Here are some key differences:

20. Fracturing Oil wells vs Gas wells

21. Fracturing Oil wells vs Gas wells

22. Fracturing Oil wells vs Gas wells Reservoir Characteristics: Oil Wells : Reservoirs containing oil often have different geological and geophysical characteristics than those containing natural gas. These differences can influence the hydraulic fracturing approach used, including the selection of proppants and the design of fracturing stages. Gas Wells : Gas reservoirs may have unique characteristics, such as higher pressures and different rock formations, which can necessitate adjustments in hydraulic fracturing techniques.

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