Chapter 1 - Gas Well Example

01-00 - Introduction (8 min.) Sample Lesson
01-01 - BHFP (Bottom-Hole Flowing Pressure) (15 min.)
01-02- Gas IPR/VLP (17 min.)
01-03 - Chokes (7 min.)

Chapter 2 - Oil Well Example

02-01 - Gas Lift Valve (14 min.)
02-02 - Gas Lift Optimization (10 min.)
02-03 - Gas Lift Curve (7 min.)
02-04 - Wellbore Pressure Loss (4 min.)
02-05 - IPR/VLP (9 min.)
02-06 - Multiwell Gas Lift Optimization Results (5 min.)
02-07 - Future IPRs & Nodal Forecast (6 min.)

Nodal Analysis Exercises / Chapter 1 - Gas Well Example

Lesson 01-00 - Introduction

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Transcript

01. Lesson 1.00: Introduction 02. Why does this matter?03. Daily BHP all wells 04. GL Injection Depth 05. IPR/VLP 06. IPR/VLP (2)07. Gradient Calc 08. Gas Lift Curve 09. Liquid Loading 10. Liquid Loading Screening 11. Gas Lift Uplift Screening 12. Gas Lift Distribution 13. Whitson⁺ Nodal Analysis 14. General Information 15. Whitson support 16. Course Agenda 17. Course Agenda (2)

01. Lesson 1.00: Introduction

02. Why does this matter?

Production engineering: it's one of my favorite parts about petroleum engineering. Why? Well, in comparison if you think about reservoir engineering doing areservoir model, there's so many inputs and there's so much non-uniqueness to characterize in the well and also the forecasts that result from that. Now if a reservoir engineer has a theory about the completion or changing something and some idea about the reservoir, it can take years to see the results of that theory if it's true and the costs of changing something about the reservoir or the completion can be millions of dollars.

03. Daily BHP all wells

Now in comparison, with production engineering, we have less variables. We can control the wellhead pressure, we have an idea of the well's productivity.

04. GL Injection Depth

If we have an experiment or theory that we want to apply about a choke change, tubing change,gas lift rate change, we can apply that and see the results almost instantly, or even just in a matter of weeks.

05. IPR/VLP

The costs for those sorts of production engineering changes are much more affordable. So I like that kind of more reasonable feedback loop, the costs, and the more certainty we have with production engineering. So that's one of the reasons I really love production engineering.

06. IPR/VLP (2)

Today we're going to be working through a lot of exercises together to learn how to use the Whitson+ engineering software to accomplish a lot of really common tasks for both gas and oil wells. So why does this matter? Well, we're gonna learn how do we automate the calculated bottomhole flowing pressures for every well. And we have oil and gas companies doing this on 5,000 wells. Every night, we'll pull in the new rates and pressures, calculate the bottomhole pressures, and those results are available for everyone to use in the morning.
For gas lift, we may wonder which gas lift valve is open now and which gas lift valve has been open historically. So we'll be able to figure out through the well's history which gas lift valve has been open. The inflow and outflow curve, basically the reservoir productivity compared to the tubinghydraulics. How do we consider things like installing tubing, changing the tubing size, changing the flow path, changing the gas lift rate, changing the choke size, changing the fluid level, changing theESP pump intake pressure or depth? All kinds of things, we're going to look at how to do these sorts of sensitivities.
Chokes: we have wellhead chokes, we also have downhole chokes. How do we predict what the rate will be with different choke sizes? We're going to cover doing this together today.

07. Gradient Calc

If we're wondering about what does the pressure profile look like down the wellbore, how much pressure loss am I losing in the lateral? We're going to learn how to do this.

08. Gas Lift Curve

Now this is actually my favorite part right here. It's called the gas lift curve. And I have to thank Devin for introducing this to me and to Whitson a couple of years ago. So really this is the relationship between how much gas lift we're injecting and how much the oil rate will increase. And basically, the peak of this curve is the highest oil rate we could ever achieve from a well at a particular gas lift rate, but we may realize that we're not operating there. We may be operating somewhere else along this curve today in the field. And so when we create this curve for every well, we can start to find opportunities. We can start to quantify what is the uplift available if we could change the gas lift rate. So we're going to spend some time doing this today as well.

09. Liquid Loading

Liquid loading: a lot of people care about liquid loading, not only for gas wells, but for gas condensate wells. And so we're going to be able to see, are we liquid loaded? When did we become liquid loaded? And even things like erosional velocity. If you've got an awesome gas well, you might be worried about erosional velocity. So we'll check that out.

10. Liquid Loading Screening

Now when you've got lots of wells and you are worried about liquid loading, how can you quickly screen those wells? Meaning, how do you make a report card of which wells are liquid loaded, which ones are not liquid loaded? So we're gonna cover this today as well.

11. Gas Lift Uplift Screening

Same thing for gas lift opportunities. Which wells are gonna respond more to a change in their gas lift rate than other wells? And so we're going to be able to rank wells by their uplift potential through a gas lift rate change.

12. Gas Lift Distribution

Now we're kind of getting into the fancy stuff, I'll say. And this is where you have a limited supply of gas lift to distribute to many wells and the question is which wells deserve more of that gas lift? Which wells deserve less of that gas lift? And so this is a process where we are going to automatically figure out how much of a limited gas lift supply should we distribute to multiple wells with the goal of having the highest total liquid rate. We introduced this about a year ago and it's really taken off like crazy and there's actually companies who are applying this every month and they're updating this to keep all the wells in their sweet spot of what the gas lift rate should be and it is making a big difference to their bottom line. OK, so that's just a bit of a teaser of what we're going to cover.

13. Whitson⁺ Nodal Analysis

My name is Graham Helfrick. I work at Whitson. I'm in Calgary, Alberta. But I used to work at Fekete for 15 years. Got to work with lots of the SAGA folks: Dave Anderson, John Thompson, Darcy, Dylan, lots of people. Today's going to be really a hands-on course where we're going to learn to actually go through these exercises together so you will be able to do this yourself.

14. General Information

The course will be about 3 hours. We're going to be focusing, like I said, on natural workflows and case studies. There's not going to be a ton of theory in here. If you are curious about bottomhole pressure theory, I know SAGA has got some great resources and there's some other ones here you could check out too.

15. Whitson support

After you take this course, if you're using the Whitson software and you get stuck, or things aren't quite looking like you expect, I would encourage you to reach out to support at www.whitson.com. Our claim to fame is a 2-minute response time and I'm not kidding about that. So the questions could be, hey, I took the SAGA course. I'm getting in my own wells. I need a hand, things aren't looking quite the same. Or hey, I've done an interpretation and I want someone to look over it to make sure it looks reasonable. Anything like that. Don't hesitate to reach out.

16. Course Agenda

We're going to start with a gas well. We're going to keep it pretty simple just to get started. How do we get the bottomhole flowing pressures for the well? Is the well liquid loaded? We're gonna use this thing called the flowingmaterial balance (FMB) and I know some of you might be familiar with that, some might not be. But this really has to do with estimating what is the current average reservoir pressure, which is something we need for production engineering and the IPR curve. So we'll talk about the flowing material balance real quickly. Our IPR/VLP curve, you might not call it a VLP, you might call it a tubing performance curve, we call it a VLP, but this is basically saying what if we flow up the casing, what if we flow up the tubing, what if we lower the wellhead pressure, how will the rate respond? So that's going to be kind of our first case, our gas well. We're going to cover chokes as well in the gas well.

17. Course Agenda (2)

For the next case is an oil well that's ongas lift. We're going to say what gas valve details are needed to predict which valve is open? What are the historical daily bottomhole flowing pressures? Of course, figure out the current averagereservoir pressure with our flowing material balance. Get a snapshot of how the well is operating now with our IPR/VLP curve. Figure out what pressure loss is occurring along the lateral of the wellbore. And then we're going to make our new favorite thing that probably is going to be your favorite thing too, is this gas lift curve. And are we underinjecting? Are we overinjecting? And we're gonna do that.
We're going to kind of wrap up at the end after Case 2 with a few of these advanced things that I mentioned where you talk about gas lift distribution for many wells. How do we do that? And I'll even talk a little bit about what's coming in the future for nodal analysis technology and spoiler alert: it has to do with future IPR curves and making pressure sensitive forecast so you can start scheduling and planning the entire wellbore life cycle.
Alright, so let's go into Case Study 1. I'll see you in there.