The 2018 41-80 Guidebook Companion is available on Amazon. I only publish this on Kindle to keep the cost <$10.
The sample problems look fine on a smartphone or computer using the
free Kindle app; it's a two problems per page format. All you need
is scratch paper and a calculator.
Problems 41-80 reference the September 2018 Guidebook (2nd printing, which again has new
sections and additional material). It also leans very hard on the SPE
Handbook (although every problem can be solved using the September 2018 Guidebook
alone).
Harder than 2016, 2017 , and 2018 1-40 versions (in my opinion) I think they offer a
challenge to most engineers. However, I still find the 2016
version the most applicable to reality. Yet I've been surprised at the diversity of opinion out there: everyone seems to have a different view of what is difficult.
Sidenote: folks currently have and are using the new Guidebook (2nd printing) and so far, so good. Myself, I haven't yet seen a copy (expecting my first ten copies on the 17th at which time I'll start mailing replacements (if they look OK) and order more as demand dictates.
Thursday, September 20, 2018
Friday, September 14, 2018
Gas Recovery: 2005 #47 (similar)
Say one has a volumetric dry gas reservoir with initial/final pressures & z-factors of 4,800/1,500 psia & 0.98/0.90. Pretty standard numbers. What's the recovery factor?
The Guidebook 13 RES 1 & 2 covers dry gas. Since recovery is just Gp/G, it's easy to move the numbers around from the given equations. One way to do this is by finding the difference between the P/z for initial and final conditions and dividing by P/z initial. In this case, it's just (4,900 - 1,700)/4,900 or 65%.
Be careful not to confuse the z-factor with FVF. If given initial and final FVF the problem is much easier as the Guidebook shows: 1-(Bgi/Bgf). It's common to confuse the two numbers because they often look alike.
The Guidebook 13 RES 1 & 2 covers dry gas. Since recovery is just Gp/G, it's easy to move the numbers around from the given equations. One way to do this is by finding the difference between the P/z for initial and final conditions and dividing by P/z initial. In this case, it's just (4,900 - 1,700)/4,900 or 65%.
Be careful not to confuse the z-factor with FVF. If given initial and final FVF the problem is much easier as the Guidebook shows: 1-(Bgi/Bgf). It's common to confuse the two numbers because they often look alike.
Monday, September 10, 2018
Temperature Force: 2005 #21 (similar)
The governing equation for the temperature force on tubing that is latched into a packer is 207ATs(Tf-Ta). It's found on Guidebook page 6 DTC 9.
ATs is merely the area of the x-section; for example 9.60 - 7.01 = 2.59 in^2. Get these numbers from the given problem, or from a packer handbook.
The temperature difference is confusing. Start with the average temperature for the well at start (Ta); easy enough to calculate (surface + bottom hole)/2. In this case, assume 145 deg F.
However, the Tf is confusing. This is the average temperature of the string when cooled to the maximum condition while injecting. It is dependent on the fluid temperature plus the injection rate & duration. Just roll with whatever a problem gives you; if given "final pumping conditions", use that. In this case let's assume 100 deg F.
Working the numbers it's 207(2.59)(100 - 145) = -24.1 Mlbf.
Note the negative sign reflects an "up" force (highlighted in the Guidebook variable box).
ATs is merely the area of the x-section; for example 9.60 - 7.01 = 2.59 in^2. Get these numbers from the given problem, or from a packer handbook.
The temperature difference is confusing. Start with the average temperature for the well at start (Ta); easy enough to calculate (surface + bottom hole)/2. In this case, assume 145 deg F.
However, the Tf is confusing. This is the average temperature of the string when cooled to the maximum condition while injecting. It is dependent on the fluid temperature plus the injection rate & duration. Just roll with whatever a problem gives you; if given "final pumping conditions", use that. In this case let's assume 100 deg F.
Working the numbers it's 207(2.59)(100 - 145) = -24.1 Mlbf.
Note the negative sign reflects an "up" force (highlighted in the Guidebook variable box).
Saturday, September 8, 2018
Guidebook, 2nd edition, TOC
Guidebook, 2nd edition, TOC.
The 5 subject areas are listed on top: Drilling -- Production/Facility/Project -- Reservoir
A significant change to the 2nd edition is a "Note" section at the end of each chapter.
The Note section includes "money quotes" or "phrases" (generally from SPE sources TS & HS).
Also included in the Note section: blank pages for personal notes.
I include this here becauseAmazon has not updated the Guidebook website image, but any Guidebook ordered from 9/7 onward should look as below and be a second edition.
The 5 subject areas are listed on top: Drilling -- Production/Facility/Project -- Reservoir
A significant change to the 2nd edition is a "Note" section at the end of each chapter.
The Note section includes "money quotes" or "phrases" (generally from SPE sources TS & HS).
Also included in the Note section: blank pages for personal notes.
I include this here because
Sunday, September 2, 2018
Streamline Simulation
An engineer studying for this year's exam emailed me an interesting question about Streamline Simulation.
It's regarding an apparent contradiction. The Guidebook quotes TS7 stating: "...there is no requirement the fluids be incompressible". Found under the "basics" section in TS7 this is fair game (author Gupta).
However, HS5 clearly states (in seeming contradiction): "...one of the key underlying assumptions in streamline simulation is that the system be close to incompressibility" (author Batycky & Thiele).
Read carefully, there is no contradiction. TS7 is clear. The quote from TS5 P1437 only says that the "system" must be "close" to incompressibility. These are not quite the same thing; note one is about "fluids", the other about the "system" (and merely "close").
I post this to show how tricky word problems can be. Be very, very careful with words. Look for exact quotes, and then carefully check for slight word change within a direct quote. And of course, check and recheck "simple" problems. Remember: a seemingly easy word problem has exactly the same weight as a 10 minute long reservoir calculation problem.
By the way, this is why many who think they did well on the PE exam still fail, and others who think they failed often pass. Paranoia is a good thing on the PE exam.
This is also why I recommend dividing each half exam into 8, 30 minute "mini-exams" of 5 problems each. One is thus forced to spend at least some extra time on these supposedly "easy" problems. And thus recheck problems otherwise deemed too easy to waste time on.
It's regarding an apparent contradiction. The Guidebook quotes TS7 stating: "...there is no requirement the fluids be incompressible". Found under the "basics" section in TS7 this is fair game (author Gupta).
However, HS5 clearly states (in seeming contradiction): "...one of the key underlying assumptions in streamline simulation is that the system be close to incompressibility" (author Batycky & Thiele).
Read carefully, there is no contradiction. TS7 is clear. The quote from TS5 P1437 only says that the "system" must be "close" to incompressibility. These are not quite the same thing; note one is about "fluids", the other about the "system" (and merely "close").
I post this to show how tricky word problems can be. Be very, very careful with words. Look for exact quotes, and then carefully check for slight word change within a direct quote. And of course, check and recheck "simple" problems. Remember: a seemingly easy word problem has exactly the same weight as a 10 minute long reservoir calculation problem.
By the way, this is why many who think they did well on the PE exam still fail, and others who think they failed often pass. Paranoia is a good thing on the PE exam.
This is also why I recommend dividing each half exam into 8, 30 minute "mini-exams" of 5 problems each. One is thus forced to spend at least some extra time on these supposedly "easy" problems. And thus recheck problems otherwise deemed too easy to waste time on.
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