Page 1 API SC 10 Denver, June 2012 – Composite Cement Testing | H. Plack | May 2012 Composite Cement Testing Dyckerhoff Germany Denver, June 2012, Heiko Plack

Page 2 API SC 10 Denver, June 2012 – Composite Cement Testing | H. Plack | May 2012 Test Programme Combinations tested (varying contents): Cementitious component: API Class G (medium coarse cement, Blaine cm2/g) API Class G + CEM I 42,5 N(medium fine cement, Blaine cm2/g) API Class H(coarse cement, Blaine cm2/g) Additive: Silica flour Medium fine (Blaine cm2/g) Coarse (Blaine cm2/g) Natural pozzolan (very fine, Blaine cm2/g)  Variations include also changing water-to-cement/blend ratio = slurry density  Blends were tested according to physical API Spec 10A requirements

Page 3 API SC 10 Denver, June 2012 – Composite Cement Testing | H. Plack | May 2012 Components Involved (Characterization)

Page 4 API SC 10 Denver, June 2012 – Composite Cement Testing | H. Plack | May 2012 Discussion Of Results Assumption (Dyckerhoff proposal): Standardization efforts target on specifying a „basic“ cement, and not a „special cement“, e.g. lightweight cement (covered by Lafarge NA proposal) = slurry density for performance testing is > g/cm3 Additives do affect the slurry density by their own absolute density differing from Portland cement higher specific surface area increasing the water demand = difficult to specify the water-to-cement/blend ratio, like for current basic cements, G and H However, most important performance requirements identified as Free fluid (slurry stability) Max. consistency 15 – 30‘ („rheology“) Thickening time Schedule 5 („pumping time“) Compressive strength („later“ strength)

Page 5 API SC 10 Denver, June 2012 – Composite Cement Testing | H. Plack | May 2012 Discussion Of Results – Conclusion (I) Blends of different cement components (reactivity / fineness) + silica flour of different fineness have been tested (+ a very fine natural pozzolan) Apart from the content of used components the water-to- cement/blend ratio has been varied respectively adjusted. It is evident that a cement manufacturer has sufficient degree of freedom to adjust physical performance properties of a composite cement by varying Cement type (reactivity) Additive fineness and content Water-to-cement/blend ratio

Page 6 API SC 10 Denver, June 2012 – Composite Cement Testing | H. Plack | May 2012 Discussion Of Results – Conclusion (II) Thus no maximum or mininim share of additive is to be specified, no water-to-cement ratio is to be specified, instead, a slurry density range is to be specified for performance testing

Page 7 API SC 10 Denver, June 2012 – Composite Cement Testing | H. Plack | May 2012 Conclusion / Suggestion (I) - Lafarge NA proposal Suggestion to specify two new API Spec 10A Composite Cement Classes with the following physical requirements: Composite cement #1 (API Class E?) → Lafarge NA results / proposal: Additives: Pozzolanic (natural + artificial), list of materials to be defined! Slurry density for performance testing: 12,0 lb/gal < SG < 16,7 lb/gal Free fluid: < 5,9% API Schedule 5 thickening time: TT > 90‘ Max. consistency 15 – 30‘:< 30 Bc Compressive strength 500 psi No chemical requirements to be specified for both new Classes!

Page 8 API SC 10 Denver, June 2012 – Composite Cement Testing | H. Plack | May 2012 Conclusion / Suggestions (II) – Dyckerhoff proposal Composite cement #2 (API Class F?) → Dyckerhoff results / proposal Considered as a „basic cement“ Additives: Silica flour + Pozzolans Slurry density for performance testing: 15,0 lb/gal < SG < 16,7 lb/gal Free fluid: < 5,9% API Schedule 5 thickening time: 90‘ < TT < 120‘ (130‘?) Compressive strength psi No chemical requirements to be specified ! However, classification as HSR grade possible if -Portland clinker used complies with HSR requirements of Classes G/H

Page 9 API SC 10 Denver, June 2012 – Composite Cement Testing | H. Plack | May 2012 Conclusion / Suggestions (III) Specifying slurry density requires a reference to API RP 10B for the test method. Mud balances usually available at all cement manufacturer‘s labs, calculation from absolute densities of components may also be considered. Requirement to provide test report along with any order shall state: Slurry density at which performance tests were conducted Water-to-cement/blend ratio at which performance tests were conducted Share of Portland cement respectively of additive Type of additive (silica flour, fly ash, natural pozzolan) + results of physical testing as specified (see above) Chemical specification ???

Page 10 API SC 10 Denver, June 2012 – Composite Cement Testing | H. Plack | May 2012 Test Results