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

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: 5 th Edition, June 2006 Most Recent Publication : 6 th Edition, May 2010

Last TG7 Status Summary – January 2010 API RP13D (5 th 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

Current Status - Executive Summary Equation and typographical errors in the 2010 edition of RP13D reported in late 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 1. Complete technical/editorial corrections and republish 2. Convene a review group to consider major updates 3. Reactivate TG7 Focus on how the document might be used Recommend Richard Meehan (SLB) as chair Consider virtual committee help 4

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 5

Sample of Current Document Tech Review 6

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. 7

Highlights of Zoomerang Survey Results 1. Include topics of interest to rheologists/academia – 48/52% 2. Primarily Excel, advanced, calculator – 59/32/9% 3. Read/not used, used, neither read or used – 48/33/19% 4. Revise or fix errors – 68/32% 5. Include derivations yes or no – 45/55% 6. USC units, SI, metric – 70/20/9% 7. Participate in TG7 yes or no– 69/31% 8

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. 9

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. 10

Current Status - Executive Summary Equation and typographical errors in the 2010 edition of RP13D reported in late 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 1. Complete technical/editorial corrections and republish 2. Convene a review group to consider major updates 3. Reactivate TG7 focus on how the document might be used Richard Meehan (SLB) as chair consider virtual committee help 11