Lecture Notes: Hydraulic Fracturing Operations and Earth Modeling

Introduction

Presenter: Dr. Ahmed Rari
Experience: 20+ years in energy and petroleum industry
Specialties: Acidizing, hydraulic fracturing, geomechanics, geothermal energy, carbon capture, storage, hydrogen technologies
Current Position: Research manager at Milit Research Hub
Academic Background: PhD and Masters in petroleum engineering from Texas Tech University
Publications: 30+ research papers
Awards: Distinguished Achievement Award from SP International (2021)

Importance of keeping the injection rate constant for accurate mathematical modeling in hydraulic fracturing
Question from previous lecture addressed: Keeping injection rate constant ensures that mathematical models for closure pressure and leak-off coefficient are valid
Detailed explanation planned for upcoming lecture on Tuesday

Pumps: 2000 horsepower on average; job size can vary based on the number of pumps and total horsepower utilized
Manifold: Connects pumps to the wellhead; has low pressure and high-pressure sections
Blender: Mixes Frack fluid with chemicals and propant
Monitoring Truck: Supervises and controls operations, including job supervisor, Frack engineer, fluid technician
Tree Saver/Isolator: Protects the Christmas tree (wellhead) by inserting a tube that can handle pressure above the wellhead’s rating

Types: Fresh water, KCl, gu (similar to beans, used in food industry)
Proppant: Sand-like material to keep fractures open, varies in size (40/70, 30/50, 20/40, 16/30)
Chemicals: Cross-linkers, breakers, friction reducers, biocides, etc.
Alternative Fluid: Slick water (used in hydraulic fracturing of shale; consists of fresh water and friction reducer)

Overburden Stress: Weight of rock points to the center of the Earth; measured by integrating density logs
Horizontal Stresses: Maximum and minimum horizontal stresses; orientation and magnitude affect hydraulic fracturing and wellbore design
Normal Fault System: Overburden stress is the greatest stress
Thrust Fault System: Overburden stress is the smallest stress
Strike-slip Fault System: Overburden is between maximum and minimum horizontal stresses

Dynamic vs Static Young’s Modulus: Dynamic from Sonic log; static from lab testing on cores
Poisson Ratio: Ratio of lateral strain to longitudinal strain, should be between 0.0 and 0.5
Calculating Stresses: Using equations involving Poisson’s ratio, Young’s modulus, overburden stress, pore pressure
Max Horizontal Stress: Difficult to measure accurately; uses wellbore failure analysis

Conducted a quiz to reinforce learning on formation damage, hydraulic fracturing goals, acid types, and proper methods to mitigate formation damage
Main takeaways from the quiz: Hydraulic fracturing aims to enhance oil and gas recovery by creating fractures that increase formation conductivity; common formation damage is due to drilling and completion operations

Complex nature of hydraulic fracturing operations and the need for precise measurements and equipment
Importance of selecting proper fracturing fluids and materials
Understanding principal stresses and their implications for well design and hydraulic fracturing

Upcoming lecture on Tuesday for further discussion on mechanical modeling and more detailed explanations

Addressed importance of converting dynamic Young’s modulus to static Young’s modulus for accurate modeling
Encouraged posting further questions under YouTube video if not answered during the session

For any further questions, post under the video on YouTube.

Next lecture: Tuesday