Chapter 1 - Introduction

1.01 - About This Course (19 min.) Sample Lesson

Chapter 2 - Basic Fluid And Reservoir Properties

2.01 - Composition, Density and Viscosity (16 min.)
2.02 - Pressure, and Pressure Gradients (24 min.)
2.03 - Real Gas Equation of State (17 min.)
2.04 - Porosity (14 min.)
2.05 - Permeability and Darcy's Law (20 min.)
2.06 - Relative Permeability (23 min.)
2.07 - Wettability and Capillary Pressure (30 min.)
2.08 - Compressibility (20 min.)

Chapter 3 - Hydrocarbon Recovery and Material Balance

3.01 - Formation Volume Factor (19 min.)
3.02 - Hydrocarbon Recovery (24 min.)
3.03 - Phase Behavior of Hydrocarbons (30 min.)
3.04 - Undersaturated Oil MBE (15 min.)
3.05 - Gas MBE (17 min.)
3.06 - General MBE (14 min.)

Chapter 4 - Inflow Performance

4.01 - Inflow Performance Relationship Concept (24 min.)
4.02 - Depletion and Skin (26 min.)
4.03 - IPR for Saturated Oil - Vogel (13 min.)
4.04 - Gas Absolute Open Flow (AOF) (32 min.)
4.05 - Tubing Performance and Lift Curves (16 min.)
4.06 - Water Drive Reservoirs (30 min.)
4.07 - Water and Gas Coning (13 min.)

Chapter 5 - Pressure Transient Analysis

5.01 - Referral To Well Testing Course (0 min.)

Chapter 6 - Production Data Analysis and Forecasting

6.01 - Production Data Analysis Overview (31 min.)
6.02 - Pseudo-Steady-State (16 min.)
6.03 - Constant Pressure Decline Curve - Part 1 (12 min.)
6.03a - Constant Pressure Decline Curve - Part 2 (29 min.)
6.04 - Constant Pressure Decline Curve for Gas - Part 1 (7 min.)
6.04a - Constant Pressure Decline Curve for Gas - Part 2 (7 min.)
6.05 - Rate Transient Analysis (26 min.)
6.06 - Production Forecasting and Reserves (25 min.)

Chapter 7 - Reservoir Modeling and Simulation

7.01 - Diffusivity Equation (28 min.)
7.02 - Dimensionless Variables and Type Curves (11 min.)
7.03 - Analytical Solutions for Radial Flow (24 min.)
7.03a - Build Analytical Model for Radial Flow in MS Excel (7 min.)
7.04 - Analytical Solutions for Linear Flow (12 min.)
7.04a - Build Analytical Model for Linear Flow in MS Excel (6 min.)
7.05 - Practical Reservoir Modeling (24 min.)
7.06 - Introduction To Numerical Models (31 min.)
7.06a - Building a Simple Reservoir Simulator (28 min.)

Reservoir Engineering Fundamentals / Chapter 1 - Introduction

Lesson 1.01 - About This Course

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Transcript

01. Lesson 1.01: About This Course 02. What to Expect from this Course 03. What does a Reservoir Engineer do?04. Fundamental Reservoir Engineering Principles 05. Examples 06. Skill Outcomes

01. Lesson 1.01: About This Course

Welcome to Reservoir Engineering Fundamentals. I'm very excited to have the opportunity to present this course. This has been a long time in the making and I think it'll be a really, really valuable course for alot of different folks. What I want to do in this short segment is just provide a little bit of an introduction as to what this course is going to be. It's somewhat unique and different than some of the other courses we have on the SAGA platform. I want to explain what to expect from it, what kind of value that I believe participants will get out of this course and set the stage for what the next few chapters are going to bring.

02. What to Expect from this Course

With all technical disciplines, we can approach the problem in a number of different ways. My preference, being a reservoir engineer with 25 some odd years of experience (and I've tried a lot of different things), I've found that my hard-won knowledge and experience has really come, in this field particularly, with keeping a practical but sort of derivation-intensive attitude and methodology. What I mean by that is, I'm really not interested in getting into advanced math and hideous differential equations. There will be a little bit of calculus and some math, but I really want to keep it fairly simple. But the equations that we do learn and the derivations that we do, I really want to pound them in solidly to build a foundation. I think that's very valuable and very important. I'm going to call it derivation intensive but practical. We're going to try and keep the equations straightforward. But the equations that we do learn in this course, you're going to commit them to memory by the time you finish the course. These are the fundamentals of reservoir engineering. You can use alot of these very simple theories and derivations to solve all manner of practical problems in the field of reservoir engineering.
So I'm going to take an approach of repetition of key fundamental concepts. That's not by accident. Everything we do in this business, particularly in the field of reservoir engineering, involves utilizing and reusing similar concepts from a technical perspective. You're going to see what some of those are in a minute. There's alot of repetition. There's alot of making sure we understand those concepts. We're going to commit those to memory. We're going to use those over and over again.
One of the outcomes of this is you will have an innate set of skills that will allow you to, probably more than anything, just be very efficient and conduct things like QA and estimate. The estimation skills are really important for reservoir engineers and I'll tell you why. It's very easy to get down into the weeds, especially now with the way complex computer models are coming out. It's very easy to get lost in the details and I don't want you to do that, OK. This course is really designed to ensure that you always keep a solid foundation. You can find your way out and always see the 30,000 ft view. So I want you to develop those practical and efficient estimation skills. I want you to be able to basically solve very complex problems approximately on the back of a napkin. That will allow you to provide quick QC/QA on very complex model simulation results, that inevitably you're going to be dealing with as a reservoir engineer in the 21st century. These are invaluable skills and honestly from my experience, these are skills that are in short supply. They will very much help you.
I think there's something for everyone in this course. If you work in the petroleum industry as a technical person, even whether you're a geoscientist, a technologist or engineer, and you're adjacent to the reservoir discipline, you're going to get value out of this course. This can be useful for new grads just entering the industry, can be useful for students, and I think even experienced reservoir engineers can get some value out of this. So I think it's somewhat of a broad spectrum for participation. I think there's alot of folks that will hopefully like this course and get some value from it.

03. What does a Reservoir Engineer do?

Let me just start from the basics. What does a reservoir engineer do? Really what I wanted to do is distill this down into something as simple as possible, because you can write a book on what reservoir engineers do. There's alot of things obviously. There's alot of details. At this point I'm not talking about details. I really want to give you the overall grand picture.
I see it very much as your typical measure-optimize-rinse-repeat cycle. I mean, that's what really reservoir engineering is all about. It's absolutely, definitely about measuring, and measuring in a practical, not necessarily precise, but we're looking for accuracy, taking measurements that make sense. And what do reservoir engineers, what are they're concerned with? Well, they're concerned with production volumes, pressures, temperatures... It's 90% of what we do. Sure we measure other things. We're interested in log measurements too, we're interested in wireline measurements, we're interested in core measurements. But 90% of what we do is production volumes, rates, volumes, pressures, temperatures to a lesser extent. What our goal is there, is to determine in-place resources and predict future performance and recovery. Very simple. You can distill it down to that.
All right. How do we do that? Well, as reservoir engineers we design and conduct well tests to obtain the necessary data. Now I'm using the term well test here in a very broad sense, OK. A well test can be something as specific as, you put a test separator on and you do a flow and buildup. In this context I'm saying it could be anything. You could conduct a well test which says I'm just going to measure production for a year and look at flowing pressures and then do rate transient analysis, or I'm going to do some other sort of test. So the idea is I'm going to collect some data and I'm going to do it in a practical way. I'm going to design a specific test or an experiment to get the data that I need to solve the problem that I need.
And then of course the other part of that is, OK, once I have this data, what do I do with it? You have to have the skills to now analyze and model that data. This is where we get into everything, from just very simple straight line plots all the way to fancy simulation models where you're doing history matching and complex work there. But for heaven's sakes, we have to get actionable results out of that. If we're just analyzing for the sake of analyzing, then we're not doing anything. This is why it's really critical that we always have our eyes on the objective. What are we trying to do here and have we collected data that are going to serve those results? The course is full of examples of what to do and what not to do, and we'll be getting into some of that stuff.
The other part of this measure-optimize piece of course is the other half of what reservoir engineers do, which is to optimize asset performance. If all you're doing is measuring and analyzing, you haven't really done anything with that data and that intel that you've gained from analyzing that data. So what do we do with that? Well, now we look at the state of what we have in our asset. Reservoir engineers, more than any other type of petroleum engineer, have to assimilate data from disparate sources. They have to understand completions. They have to understand certainly what's going on on the surface. Rate restrictions on the surface and operational constraints, as well as the subsurface. They have to understand economics. They have to understand the costs of producing. They have to understand the time value of money. They have to understand things likeNPV, IRR. These are 3 letter acronyms for Net Present Value and Internal Rate of Return. These are things that reservoir engineers need to understand. We have a whole section in the course on economics and understanding these things.
So it's really their task to design or help design (or advise on at least) a field development strategy. Whether a reservoir engineer has direct control over field development strategy really depends on the organization. I've seen some organizations where reservoir engineers have full control over that. I've seen other organizations where they simply advise. At the end of the day it doesn't matter. You need to use your skill to the best of your ability within the constraints of your organization. As a reservoir engineer, you're going to be pulled into these discussions on helping design these strategies. That could be anything from, in the unconventional realm, if we're designing the next pad, what does that look like? What's the spacing on the wells? What sort of vertical targets should we be going for? What's the frac intensity? What does a completion look like? These are all questions that need to be answered. Reservoir engineers are right in the center of answering and helping answer those questions.
The other piece is what we call enhanced recovery schemes. So there's lots of stuff. There's whole branches of reservoir engineering that are just around secondary recovery, waterflooding, enhanced recovery like EOR, IOR. These are also important concepts that reservoir engineers take on to try and improve. The thinking here is that, you know, Mother Nature gives you this reservoir. If you poke a hole in the ground and start producing from the wellbore, you get your primary recovery. Well, reservoir engineers are tasked with how do we make that better? Can I use the concepts of thermodynamics, chemical reactions, just simply physics. Gravity, things like that. Displacement. How can I improve, how can I add a wedge to that production and make that overall recovery better? That's a huge branch of reservoir engineering. We're going to talk about some of those things in the course as well.

04. Fundamental Reservoir Engineering Principles

How does a reservoir engineer do all of this? This is one where, again, there's whole textbooks devoted to this subject. I don't want you to read a textbook. I want you to use a textbook as a support and as guidance and as lookup material, but you need to do more than that. You need to have some of these skills just innately in your brain to help solve some of these problems. My role as an instructor here is to really simplify it for you. Bring it down to first principles and try and understand what are the basic reservoir engineering principles that really guide all of this stuff, everything I've talked about so far.
And there's 3. There are 3 basic fundamental reservoir engineering principles that will essentially guide everything that you do as a reservoir engineer. Maybe you know what they are already (some of you I'm sure you do).
You have your equation of state which really describes the pressure, volume, temperature relationship. So how does a gas behave under different pressure, volume, and temperature. How do more complex fluids (gas condensates, volatile oils, black oils, water), we need to understand. Because as reservoir engineers, we're dealing with these fluids. A big component of what we do as reservoir engineers is we have to understand what happens to a fluid when it comes from the subsurface and goes to the surface. Or vice versa, if we're injecting it back into the reservoir. What happens in that sense. That's really your equation of state component. Understanding your fluids, understanding your PVT. The first part of the course will be devoted to understanding that stuff.
Next section is your material balance. Essentially, this is just conservation of mass. Reservoir engineering is all about, you have a reservoir in the subsurface, you're going to produce something out of it, and there has to be a conservation of mass. What's the language of that conservation of mass? Well, in most cases that language is in pressures, because pressure is something that we can measure fairly accurately in a reservoir and it's a very good indicator of mass loss or mass gain in that reservoir. That material balance, the language of it is often done in pressures. That'll be the next section in the course, where we talk about all that stuff. What you'll find with material balance is it comes into almost everything we do. You don't have to be doing a per-se material balance analysis to be using the material balance concept. It comes into production analysis, it comes into well test interpretation, it comes into reservoir simulation, it comes into decline curve analysis (sometimes). It's a very pervasive concept and we use it everywhere.
Finally, we have Darcy's law. If you're not a reservoir engineer or if you are, either way I'm sure you've heard of it. Darcy may well be the most famous name, Henry Darcy, in petroleum engineering, certainly in reservoir engineering. He's sort of the hero of reservoir engineering, although he was never involved in petroleum exploitation at all. Darcy's role was largely as a groundwater hydrologist. But his observations and experiments that he conducted back in the 1800s really define how we solve petroleum problems now. So this is a statement of the conservation of momentum. Material balance is a statement of the conservation of mass. Darcy's law, which in its more complex form can be extended to Navier Stokes law, but Navier Stokes has a whole bunch of stuff in it that most of the time we don't need for petroleum engineering purposes. So we use Darcy's law. That seems to solve 95% of our problems.
The combination of these 3 fundamental concepts will solve almost all of your practical problems in reservoir engineering. You can be a superhero reservoir engineer if you have a very solid fundamental understanding of these 3 concepts. And that's my goal in this course, is to give you that.

05. Examples

All right, let's look at a few examples. Resource assessment, recovery estimation, depletion assessment. These are major roles and tasks that reservoir engineers undertake. You can do that with equation of state and material balance.
Inflow performance assessment. If you're selecting surface and downhole equipment for optimum production. You would do this in connection with a production engineer, if you're a reservoir engineer working with a production engineer to solve these problems. That's essentially equation of state and Darcy's law to solve those problems.
And things like RTA, PTA, reservoir simulation. These are the full combination. That's the more complex problems that are using all 3 together. You have equation of state, material balance, Darcy's law all together. What ends up happening, when you put those all together from a mathematical perspective, is you have something called the diffusivity equation. The diffusivity equation was solved back in the 1940s by Maurice Muscat. So all of the math behind reservoir engineering, it's been around for decades. It's been there since the beginning. It's not necessarily a requirement to really go into all that math and understand it, but we definitely need to know where to pick and choose. And it all starts from the diffusivity equation, so we will get into some discussion on that, although not to the level that some textbooks teach it.

06. Skill Outcomes

All right. Last but not least, skill outcomes. What should you expect out of this course? How are you going to beef up your skills? Like anything else, you will get out of it what you put in. There are some interactive components to this course. There's some competency assessment tools that will help you grade yourself and help you understand whether you're learning the concepts and how well you're learning the concepts.
I'll make a couple of important comments here. A good reservoir engineer is much more than somebody who's proficient at running complex modeling or visualization software (I alluded to this before). You need to have those innate skills in your brain to help estimate, help do QA/QC, make good decisions. We'll always be able to see the 30,000 ft view. And these days, you have to have that skill - the ability to run those complex models. You can't be a good reservoir engineer, no one's going to hire you if you don't know how to run the software. That's a necessary but not sufficient skill-set to be a good reservoir engineer. I'm going to tell you through my experience (and I've worked with and I've had dozens (if not 100s) of reservoir engineers either under my direct supervision or working with them in some capacity over the years), the skills that are required (the real good, solid estimating skills) are hard to find. There aren't that many folks that really do this well.
That's why I decided to put a course like this together. I really want to help folks develop some of these skills a little bit better. Now you're a dynamite reservoir engineer if you can combine those 2 together. If you're really good with running the software, but you also can take that step back: look at first principles; question the results; develop intuitive estimating skills; always looking at results; always looking for results; you're focused on the objective; you're focused on actionable outcomes when you're measuring (designing tests and things like that). That's what makes a good reservoir engineer. And again, those skills are hard to find. So let me underline that and say, Yes, very important!
That is really my description of the course. Hopefully everybody, from looking at this, gets an understanding of what to expect in this, and I'm very much looking forward to working with you all in getting through the course. Thank you very much.