Well Testing Analysis Strategy

Well Testing Analysis 1. The syllabus is very limited in this section but demands a lot of understanding. So multiple sources and multiple reading of the same is advised. Book Sources: John Lee, L.P Dake ( Fundamentals of Reservoir Engg.), Tarek Ahmed (Reservoir Engineering Handbook) 2. The formulae, which seem apparently complex to commit to memory, are extremely important and questions have been asked directly from the formulae. Formulae have to be remembered in Darcy units and Field units for concepts and numericals respectively and this needs practice. 3. Fluid Flow in Porous Media: Extremely important topic as it lays the foundation for other topics. Start with Chapter 5, 6 and 7 (Up to 7.5 (c)) of L.P Dake. All derivations and theory in L.P Dake are explained employing Darcy’s units and hence it is imperative for a sound understanding. You may now start with Lee Chapter 1(for practice in field units). It is highly advised to practice the solved numericals wherever they feature in the text. 4. Pressure Buildup Tests: Cover Lee up to 2.8. Incomplete perforation and hydraulic fracture cases may be ignored. Basic idea of Section 2.9 is required. Numericals will not typically be asked from this section. So just a fair understanding of the textual theory is recommended. Section 2.10 is more deserving of some numerical practice, though chances are much less as compared to other sections. Understanding the theory is, again, very important. 2.11 and 2.12 can be ignored. 5. Flow Tests: Easy to understand and limited to 4 pages. Cover up to Section 3.3 only. It is important to appreciate at this point that, at least 75% of the syllabus is over by now in just 3 chapters. SO cover these religiously. 6. Type Curve Analysis: Though a basic understanding is always good, it can be ignored completely from GATE point of view. The best you can do is to remember the terms associated with each type curve for some unprecedented match type questions. Numericals will not be asked in all likelihood. 7. Gas Well Testing: I would advise to cover this topic from Tarek Ahmed as the language and theory is easy to follow. Cover Radial flow of compressible fluids for each flow regime as given in the chapter ‘Fundamentals of Reservoir Fluid Flow’. Numericals are important here. Once you are done with TA, you can cover the numerical from Lee directly without the theory. 8. Other Well Tests: Read the text and keep some notes handy for each of the tests especially those related to the conditions for use and limitations. Only theoretical match type questions can be expected from here. No need for studying graphs and numericals. 9. It is advisable to keep revising Tarek Ahmed for the portions that you have already studied under Reservoir Engineering. Certain things, for example, the equation relating initial pressure, average pressure and time for a semi steady state condition, in field units, is found only in TA. Once the above are covered, you can go for a selective reading of TA.