TG7 Issues on RP 13D Rheology and Hydraulics

1. TG7 Issues on RP 13D Rheology and Hydraulics Mario Zamora Exploration & Production Standards Conference API Subcommittee 13 June 27 – July 1, 2011

2. API RP 13D – TG7 • Original Charge: Update and modernise API RP13D Bulletin Rheology and Hydraulics of Oil-well Drilling Fluids • Intent: Allow users to use spreadsheets to calculate ECD, pressure losses, hydraulic parameters, hole cleaning, surge/swab, optimized hydraulics, and perform rigsite monitoring. • Last Major Revision: 5th Edition, June 2006 • Most Recent Publication: 6th Edition, May 2010

3. Last TG7 Status Summary – January 2010 • API RP13D (5th Edition) published June 2006 • NWI submitted to API for editorial corrections • Editorial changes and corrections completed • Equations corrected • Table references updated • Duplicated table numbering corrected • General typos corrected • Document approved by TG7 Members & SC13 • Final version completed (January 2010) • WG requests approval to go into hibernation

4. Current Status - Executive Summary • Equation and typographical errors in the 2010 edition of RP13D reported in late 2010. • Ad hoc group of 5 “experts” reviewed document for technical and editorial errors (details with SC 13 Chair) • SC13 chair coordinated 42-repondent Zoomerang survey (details with SC 13 Chair) • Recommendations • Complete technical/editorial corrections and republish • Convene a review group to consider major updates • Reactivate TG7 • Focus on how the document might be used • Recommend Richard Meehan (SLB) as chair • Consider virtual committee help

5. Recommended Focus on Document Use • Rheologists- study & explain • Chemists- formulate & commercialize • Modelers- measure & relate • Software developers- compile & disseminate • Engineers - plan & optimize • Wellsite Personnel- apply & adapt

6. Sample of Current Document Tech Review

7. Highlights of Current Document Tech Review • Errors found in over two dozen equations, primarily related to units, general typos and inconsistencies with symbols table. • Needs critical review for consistency among the different sections. • Variables used in the text and equations should be consistent with how they are defined in the symbols list. • Rheology is a science. In several places the term should be changed to rheological property or viscosity. • Not all the units in the SI-unit column are SI-units. • Shear rate should be denoted by “gamma-dot”, not “gamma”. • Effects of drill string rotation are not properly described. • Multiple issues with temperature profiles – unable to reproduce calculation in appendix. • Need PVT data on more base oils.

8. Highlights of Zoomerang Survey Results • Include topics of interest to rheologists/academia – 48/52% • Primarily Excel, advanced, calculator – 59/32/9% • Read/not used, used, neither read or used – 48/33/19% • Revise or fix errors – 68/32% • Include derivations yes or no – 45/55% • USC units, SI, metric – 70/20/9% • Participate in TG7 yes or no– 69/31%

9. Highlights of Zoomerang Survey Items to Add • Effect of rotation on pressure loss. • Models of structure build-up and breakdown. • Add cuttings slip velocity, ECD prediction, ROP optimization, cutting annulus load, CCI. • Compressibility of oil and effect on mud weight. • How it affects the elastic modulus (G ') hydraulics during the transport of cuttings, and the maximum concentration of solids in the system. • Can make the system use a spreadsheet to calculate hydraulics but also must have a way to do it by hand. • Document needs to be accurate. • Fix all errors, reissue, and upgrade with new and better methods. Write as industry RP - not too complex, but completely useful for the desk engineer or rig supervisor. • Not sure about spreadsheet format - let committee decide on best format.

10. Highlights of Zoomerang Survey Charge / Scope • Minor revision of 13D only to include new topics and make the applications more widely used by industry. • Scope should be for the use of wellsite and office engineers, but involvement of academics and rheologists should be considered to expand and ensure current, most relevant techniques are offered. • Purpose of TG7 is to review the latest version RP-13D to determine if there are sufficient technical changes to warrant major revision of the document. • The task would be to “render the document suitable for engineering calculations, make equations and units consistent throughout”. • Review RP13D to correct typographical errors and incorrect information, and include updated drilling fluids rheological information and calculations. • Make for rig site & office engineers. “Rheologists” could make their own more technical RP if desired.

11. Current Status - Executive Summary • Equation and typographical errors in the 2010 edition of RP13D reported in late 2010. • Ad hoc group of 5 “experts” reviewed document for technical and editorial errors (details with SC 13 Chair) • SC13 chair coordinated 42-repondent Zoomerang survey (details with SC 13 Chair) • Recommendations • Complete technical/editorial corrections and republish • Convene a review group to consider major updates • Reactivate TG7 • focus on how the document might be used • Richard Meehan (SLB) as chair • consider virtual committee help