Chapter 1 - Introduction to the Course and a Brief History of Fracturing

01-01 - Hydraulic Fracturing Introduction (18 min.) Sample Lesson
01-02 - Course Objectives (12 min.)
01-03 - What is Hydraulic Fracturing? (20 min.)

Chapter 2 - Equipment and Operations

02-01 - First Experimental and First Commercial Frac Treatments (27 min.)
02-02 - Treating Iron and Equipment Rig-Up (21 min.)
02-03 - Job Setup & Safety (39 min.) Quiz: 02-03 - Job Setup & Safety

Chapter 3 - Stresses and Conductivity

03-01 - The Many Stresses/Pressures Experienced in Fracturing (11 min.)
03-02 - Stress Magnitude (14 min.)
03-03 - Effect of Geologic Structures (8 min.)
03-04 - Stress Logs and Borehole Breakouts (17 min.)
03-05 - Determination of Stress Differences (13 min.)
03-06 - Stress Measurements (8 min.) Quiz: 03-06 - Stress Measurements

Chapter 4 - Reservoir Response, Post Frac Production, and the Effect of Transient Flow

04-01 - Variables Affecting Post -Frac Productivity (26 min.)
04-02 - Folds of Increase for Acid Fracturing (15 min.)
04-03 - Demonstration of Stress & Proppant Conductivity (Frac School 1 Problem) (9 min.)
04-04 - Frac School 1 Problem - Part 2 (3 min.) Quiz: 04-04 - Frac School 1 Problem - Part 2

Chapter 5 - Fracture Geometry Basic and the Major Fracture Design Variables

05-01 - Fluid Selection - 4 Cases (14 min.)
05-02 - Basic Theory - Material Balance Equation (14 min.)
05-03 - Fracture Geometry and Net Pressure (6 min.)
05-04 - Apparent Toughness (9 min.)
05-05 - In-situ Stress variations vs Fracture height (9 min.)
05-06 - Lumped Pseudo 3D Model (7 min.)
05-07 - Sensitivity Problem Exercise and Results (17 min.)

Chapter 6 - Fracture Design Variables (HECKµQ)

06-01 - Fracture Height (29 min.)
06-02 - Frac School #1: Frac Geometry (5 min.)
06-03 - Modulus (16 min.)
06-04 - Fracschool #1 - Modulus Estimation (7 min.)
06-05 - Fluid Loss (26 min.)
06-06 - Frac School #1 - Fluid Loss Estimation (6 min.)
06-07 - KIc (6 min.)
06-08 - Fluid Viscosity (20 min.)
06-09 - Frac School #1 - Fluid Viscosity (2 min.)
06-10 - Pump Rate (10 min.)
06-11 - Frac School #1 - Pump Schedule (7 min.) Quiz: 06-11 - Frac School #1 - Pump Schedule

Chapter 7 - Treatment Design Options

07-01 - Perfect Transport Fluids (19 min.)
07-02 - Tip Screen-out (TSO) Designs (12 min.) Quiz: 07-02 - Tip Screen-out (TSO) Designs

Chapter 8 - Fracture Closure Stress & Pressure Decline Analysis

08-01 - Pressure Analysis Workflow (14 min.)
08-02 - Micro-Frac Stress Tests (26 min.)
08-03 - Step-Rate Tests (27 min.)
08-04 - Frac School #1 - DFIT Injection-Decline Stress Test (13 min.) Quiz: 08-04 - Frac School #1 - DFIT Injection-Decline Stress Test

Chapter 9 - Minifrac Pressure Decline Analysis

09-01 - Bottomhole Treating Pressure (17 min.)
09-02 - Nolte-Smith Diagnostic Log-Log Net Pressure Plot (18 min.)
09-03 - Nolte-Smith Field Examples (3 min.)
09-04 - Interpreting Shut-In Pressure Decline (12 min.)
09-05 - Frac School #1 - Pressure Decline Analysis (22 min.)
09-06 - Minifrac Pressure Decline Analysis (11 min.) Quiz: 09-06 - Minifrac Pressure Decline Analysis

Chapter 10 - Proppant Selection

10-01 - Importance of Conductivity (25 min.)
10-02 - Proppant Types (8 min.)
10-03 - Proppant Usage and API Standards (11 min.)
10-04 - Natural Frac Sands (25 min.) Quiz: 10-04 - Natural Frac Sands

Chapter 11 - Fluid Chemistry and Selection

11-01 - Fracturing Fluid Chemistry (16 min.)
11-02 - Guar & Guar Based Derivatives (22 min.)
11-03 - Other Gellant Chemical Structures (14 min.)
11-04 - Breakers (20 min.)
11-05 - Clay Control Agents (15 min.) Quiz: 11-05 - Clay Control Agents

Chapter 12 - Fracture Diagnostic Techniques and Tools

12-01 - Post-Frac Temperature Surveys (9 min.)
12-02 - Post-Frac Radioactive Tracers (19 min.)
12-03 - Micro Seismic Monitoring (24 min.)
12-04 - Chemical Tracers (6 min.) Quiz: 12-04 - Chemical Tracers

Chapter 13 - Perforating and Perforation Strategies

13-01 - Normal Perforating Gun Questions (15 min.)
13-02 - Limited Entry and Perforation Erosion (9 min.) Quiz: 13-02 - Limited Entry and Perforation Erosion

Chapter 14 - Treatment Execution/Quality Control and Safety

14-01 - What Is Quality Control? (14 min.)
14-02 - Environmental Stewardship (39 min.)
14-03 - Post Frac Quality Control (5 min.)
14-04 - Fracturing Safety: There Are No Clowns (6 min.) Quiz: 14-04 - Fracturing Safety: There Are No Clowns

Chapter 15 - Big Problem No. 1

15-01 - Estimate Design Variables (17 min.)
15-02 - Fracturing Pressure Data & Pressure History Matching (20 min.)

Hydraulic Fracturing / Chapter 1 - Introduction to the Course and a Brief History of Fracturing

Lesson 01-01 - Hydraulic Fracturing Introduction

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Transcript

01. Lesson 1.01: Hydraulic Fracturing Market

Good morning, everyone. We're here to start a discussion on hydraulic fracturing, prop fracturing. Maybe we'll spend 5 minutes on acid fracturing but this is primarily about prop fracturing.

02. Fracturing Introduction

And start out with some pictures. On the left there we see a vertical prop fracture. This is along a fjord in Norway, near Stavanger, Norway. And if we could zoom in there, see a young lady out there. And I've been there and the best I could do was lay on my stomach and peek over the edge. So that young lady is very brave. And then we have a horizontal prop fracture, and finally just a picture. I have worked on wells in New Zealand and Brazil, where we drill from onshore to an offshore location. I've never heard of anyone drilling from an offshore to an onshore application. But prop fracturing is very common in offshore environments, and not just for the frac packs in high permeability sands. More and more lower permeability formations are being developed offshore, although lower meaning 2 - 5 md, not microdarsies.

03. Natural Fractures

But there's lots of fractures in the world. Natural fractures, of course, very common in some formations. Here we see an outcrop. You see a lot of vertical natural fractures. And in core, we see different types of natural fractures. One I find kind of interesting is the bottom right there. It's labeled compacted. I'm not sure what compacted means. I'm not sure how you generate a natural fracture with that kind of curvature to it. But I presume it's some sort of shear fracture. But you also see in the top right, some horizontal natural fracturing, bedding plane parallel natural fractures. And natural fractures can play a big role in hydraulic fracturing. They put a real monkey wrench into hydraulic fracturing. It changes the fluid loss. It may create a complex fracturing. Hydraulic fracturing / prop fracturing and natural fractures do not coexist well, although in some formations the combination is crucial to the production. The Barnett shale, the first unconventional formation, highly natural fractured in the combination of prop fracturing and the naturalfracture system was crucial to the development of that formation.

04. Hydraulic Fracturing: International & Offshore

Look at hydraulic fracturing international and offshore. And we can see the dollars increasing from 2020 there to 2025, nearly more than doubling. Primarily Schlumberger and Halliburton and then other, although now Liberty would be larger than Schlumberger. They took over Schlumberger's North American operations.

05. Hydraulic Fracturing: US Land Market

U.S. Land market: Again, we see the dollars peaking there around 2022 and then declining a little over the next years.

06. Hydraulic Fracturing: Global 2024 Revenues

Globally, by service company, we can see Halliburton and then Liberty and then other companies; Schlumberger is down around 4th or 5th there. So a lot of service companies, although the top 4 or 5 really dominate the market.

07. Hydraulic Fracturing: US Active Frac Spreads

Going back to the US, look at active frac spreads. So it peaked around 2018, 2019. 2020 COVID came along and everything crashed. And it's slowly recovering. Although I don't know current numbers but it's nowhere near its peak. Part of that is efficiency. Where they have one frac spread working on 2 or even 3 different well heads, and they simply switch from one to another to another, so they're pumping virtually continuously. So they've done a lot more fracs with fewer fleets. Just like drilling, the rig count has never recovered, but the footage drilled is increasing. Just tremendous gains in efficiency. That'd be an interesting statistic to have actually.

08. Hydraulic Fracturing: US Market by Quarter

This is just looking at the U.S. market by quarter from the different formations dominated by the Permian Basin, south Texas, the Eagleford, and other formations. Again, we see things crash in there with COVID and then recovering.

09. Hydraulic Fracturing: US Spending Distribution

Looking at spending distribution. Frac is the dominant one. But water is a huge cost. So the spending distribution is split among a lot of different items there.

10. Average Water Usage by Well Type

Average water use for horizontal gas wells up in the millions of gallons; Horizontal oil, a little bit less; And then vertical wells, much, much less. Of course, vertical wells typically only have 1 or 2 stimulation treatments, where a horizontal well may have 30 stimulation treatments.

11. Wells Drilled per Pad

Another big change in recent years (and this is for 2021) is pad drilling, where we see multiple wells drilled from pads, with dominantly 2, 3, or 4 wells drilled from a single pad. And again, that's contributing to the efficiencies in drilling that have been developed.

12. Frac Spend on 15k ft Wolfcamp Permian Horizontal Well

Looking at the frac spend for a typical Permian well, a Wolfcamp well. We see trucking, pumping service there is about $1.7 million. Where is the sand? Sand is $3 million. So sand is the primary cost for an unconventional frac job. And that's why you've seen people switch to using local sands, which traditionally would have been considered really trash. And compared to the Northern Ottawa white sands, they're really poor stuff. But still, the cost factor is so big for the unconventionals where nearly half of the spend is on the sand, which is always been very surprising to me.

13. Change in Completion Strategy

Change in completion strategy. I find this interesting: Lateral lengths increased 50%; Stages have nearly doubled; Perf cluster per stage is more than doubled.Proppant, where is proppant mass per lateral foot? It has nearly tripled; Proppant mass is nearly quadrupled. And yet actually, 365-day cumulative oil equivalent has only gone up 28%. So obviously saying it's a major cost and it's nearly quadrupled, but it's only given us 28% better production. To me that implies something about our design process. We're not getting the benefit from quadrupling the cost of our frac jobs and only getting a 20% increase in production. So I think there's a lot of room for improvement in frac design for the unconventionals.

14. Average Lateral Length

Average lateral length has increased and increased and increased to, I don't know, ridiculous extremes. Now they're drilling some U-shaped wells where they drill 10,000 ft north and then they make a big U-turn and drill 10,000 ft south. And OK, I'm impressed that the drillers can do it. The biggest change I've seen in drilling in my career, when I first got involved in completions and fracturing, drillers only knew one word: NO. Now you tell them you want to drill figure 8's and they'll just sit down... OK, this is what it'll cost and we'll do it. Just a total mindset change in drilling that has fueled the unconventional developments.

15. Use Technology to Improve the Completion Efficiency

This is looking at some data for refracturing masking poor completion efficiencies. 10 clusters per stage, 3 perforations per cluster. The darker colored perforations use microproppants. And maybe the microproppants are giving us some preferential distribution. Based on perforational erosion, we see what appears to be much better distribution of the proppant. If we look at, I'm having a hard time reading the number, but #20 there, the first perf cluster looks like it took most of the sand. We had a runaway frac there. If we get a run away frac, then it erodes the perf more, it goes more there, which erodes the perf more. The microproppant may be doing some preferential erosion or breakdown. A possibility of improving. These are the kind of things I think we need to look at. Why have our masses of proppant not improved production? Well, if the masses of proppant are all going into one stage, you wouldn't expect a major improvement in production. And so I think there's a lot we need to learn about our completion of these unconventional wells.

16. What is it that a Frac Engineer Does?

Next, what is it that a frac engineer does? Well, if any of you have worked offshore, you do a lot of this: Hurry up and wait. Oil industry people are not very expensive and time is very expensive, so that looks like a frac engineer working offshore. And then once you're through with your fracturing. This is a picture of Jim Abel (I worked with a little bit on the North Slope), and this is what he does in his off time, is build crazy motorcycles (haven't seen Jim in a while. I don't know if he's still driving motorcycles or not). And this is my partner, Carl Montgomery, who you'll be meeting later. And Carl is a dinner table entertainer, hanging spoons. And I'm not quite sure how he does it. I've tried it once or twice and it doesn't work. So he must have electrostatic oil in his skin or something.

17. What is it that a Frac Engineer Should Do?

But what we should do, our primary objective is of course to maximize productivity; Produce at the designed flow rates or better; And longevity. We mentioned earlier that refracs are a mask for poor completions. We need to consider, will acid fracturing work at this stress, or will the stresses close the acid edge frac? Or proppant: As we draw down the reservoir, put more and more stress on our proppant, will it crush and we'll have to do refracs? So we need to plan for the life of the well to minimize workovers. And basically economics. Fracturing is an economics process. I can drill 1 well or I can drill 2 wells, or I can drill 1 well and frac it. I can do a bigger frac. There's really not a good technical answer to frac design. It is an economics process. All we're doing is increasing rate. We're not manufacturing oil or gas.

18. Course Objectives

Our objective for this course is to look at the underlying physics, provide an understanding of the design, production performance, evaluation, and operational execution of hydraulic fracturing. But we wanna do that within an integrated concept of fracturing design. I've been assigned the task of fracturing this well, blah, blah, blah. Where do I start? What do I do? What do I do first? And what do I do second, et cetera? And we want to look at a logical step-by-step approach. Looking at the underlying physics, what data is important, where do I get that data, and how do I apply that to my frac designs. And we'll try to work through some design examples as we go.

19. Course Outline

Outline, we're doing the introduction now. I'm really not in there. Carl will come along and talk about one part of fracturing, the operations. Then we'll get into some geomechanics and talk about rock stresses. We'll pretend to be production reservoir engineers for a while and talk about post-frac production. Then get into fracture geometry. What are the major design variables in fracturing? Fracture height, the modulus, fluid loss, fluid viscosity, pump rate, all culminating in building a treatment schedule. Actually, selecting proppant and fluid types is part of this design process, but we're gonna pull that out and talk about thesefracture materials separately. And then we will look at other ancillary topics, perforating for fracturing and treatment execution, et cetera. If anything, treatment execution gets a little bit short shrift in this course. We'll talk in a minute about the tripod of fracture design. And operations is one of the legs, and it's really the major leg. If you can't do it in the field the way it's designed, all your theory and design work is not worth much. And so we could spend half the week on that, but unfortunately time doesn't allow that.

20. Mike Smith: Background

So my name is Mike Smith. I'm president of NSI Technology. We're a small engineering firm specializing in hydraulic fracturing, engineering, and software and training. Background: I went to Rice University in Houston as a mechanical engineer. I would love to design the downhole tools for frac packing. To me, that's a dream job for a mechanical engineer. But that's not what life dealt me. I spent some time in the US Army, and so we'll be following the US Army training techniques here: We're gonna tell you what we're going to tell you; Then we're going to tell you; And then we're gonna tell you what we told you, so you'll have 3 chances. Back to Rice University again, and 36 years, unfortunately is a little out of date. The years keep adding up. I'm giving a talk here in Calgary this week on the Wattenberg story which is coming on 50 years ago, so a little bit of a history lesson. We may have time to go through that case history later. I did a lot of work in the North Sea and various other outside work. Tennis, no more, COVID and knees put an end to that. And water skiing, no more at all. But I still do swim with my labrador puppy.