1. NOVEL CHEMICALLY BONDED PHOSPHATE CERAMIC BOREHOLE SEALANTS FOR ARCTIC ENVIRONMENT NOVEL CHEMICALLY BONDED PHOSPHATE CERAMIC BOREHOLE SEALANTS FOR ARCTIC ENVIRONMENT Presented By : Nilesh Limaye, UAF. Presented By : Nilesh Limaye, UAF. Principal Investigator : Shirish Patil, UAF. Principal Investigator : Shirish Patil, UAF. Partner Principal Investigator : Arun Wagh, ANL. Partner Principal Investigator : Arun Wagh, ANL. Industrial Participant : Jeff Dawson, BJ services. Industrial Participant : Jeff Dawson, BJ services. January 23, 2007 January 23, 2007 Fairbanks, AK. Fairbanks, AK.

2. INTRODUCTION: Unique cementing difficulties in permafrost and gas hydrate zone at ANS. Problems associated with Conventional Portland cement concretes. Development of Ceramicrete. Advantages of Ceramicrete over Conventional Portland cement. Various tests carried out at ANL, regarding Ceramicrete properties. “Argonne Phosphate cement”.

3. Tests done at BJ: Flash setting of Ceramicrete Void spaces

4. Tasks Achieved (09/05-12/06) : Ceramicrete application for cementing oil wells in ANS Economic Analysis of well cementing. Determination of radius of thawed-permafrost zone and temperature distribution in thawed zone around well bore at ANS. Task remaining: laboratory tests at ANL, regarding flash setting of mixture of Ceramicrete (95%) and Conventional Portland cement(5%). Tests at BJ services

5. Ceramicrete application for Cementing oil wells :  Ceramicrete formulation used : ( Banerjee,2005) Ceramicrete Formulation Weight % MgO25% KH 2 PO 4 27.20% C-Class fly Ash10.20% Wollastonite10.20% Boric Acid0.09% Water27.20% Total100%

6. Economics of well cementing : 1.Example of a typical oil well at ANS. 2. Calculation of annular volume between casing and bore hole for different zones. 3. Calculation of amount of Ceramicrete required for cementing oil well. 4. Calculation of raw material cost and thus, cost of production.

7.  Consider a typical oil well that is to be drilled at ANS at a depth of 3500 feet.  Typical oil well configuration at ANS: Well depth 3500Ft. Permafrost Zone 1800Ft. Stable Hydrate Zone 1700Ft. Diameter Size open hole in permafrost Zone 26’’ Surface Casing in permafrost Zone 20’’ hydrate zone 22’’ intermediate casing 14’’

8. Permafrost zone 1800 feet. Stable Hydrate Zone 1700 feet Ceramicrete Dia.20 ” Dia.26” Dia.14” Dia.22” Surface Casing Casing shoe Intermediate Casing

9. Annular volume between casing and zones:  Annular volume between Surface casing and permafrost zone or Intermediate casing and Stable hydrate zone Annular Volume = 0.785 * (Dh 2 – Dc 2 ) *H. Where, Dh = Diameter of permafrost zone or Stable hydrate Zone Dc= Diameter of casing H = Depth of each zone (permafrost & stable hydrate).  Total annular volume = annular volume between surface casing / permafrost zone + Intermediate casing / Stable hydrate zone

10.  Thus, Total annular volume for given well = 152.34 m 3. Ceramicrete requirement for cementing given well:  The Ceramicrete slurry density for formulation used is found out to be 1.9 gm/cc or 1900 kg/m 3. (Banerjee, 2005)  Amount of Ceramicrete = Density * Volume = 152.34 (m 3 ) * 1900( Kg/m 3 ) = 285.45 MT.

11. Calculation of raw material cost:  Amount of Ceramicrete required for cementing 1well = 285.45 MT.  We consider 8% more cement production considering various loses involved in actual cementing application. i.e. Amount of cement production = 308.28MT. Ceramicrete Formulation:Weight % Tones$ MgO25%0.2576.9538,475.00 KH 2 PO 4 27.20%0.27283.72115,906.10 C-Class fly Ash10.20%0.10231.39784.89 Wollastonite10.20%0.10231.3918,837.36 Boric Acid0.09%0.00090.27702218.29 Water27.20%0.27384.02 Total100%1.00308.28174,221.64

12.  Now, if we consider 10,20,30,…. such oil wells to be drilled at ANS (Ceramicrete Production on bulk basis), the Raw material cost would be: Number of wellsProduction (tones)Raw material cost ($) 1308.28174,221.64 103,078.001,853,910.79 206,1563,695,505.28 309234.005,528,413.39 4012,312.007,364,041.12 5015,390.009,199,193.36 6017,100.0010,217,638.26 7019,950.0011,911,844.45 8024,621.5314,701,080.44

13. Problems associated with current formulation of Phosphate cement: (@ Tomball meeting) 1.Failure in consolidation test. 2.Cement contamination / flash setting. “Argonne Phosphate cement” 1.Composition without cement contamination 2.Composition with cement contamination Range of amount of fly ash. 10% Portland Cement. Water to cement ratio :33.12%

14. Powder Components 24-h compressive strength Argonne's novel phosphate Binder Class C fly ash Boric acid (% binder) OPC (Type I) 50 3.7501024 40503.7510657 40502.510657 45 3.7510657 50403.75101052 Test Results: Compression strength in consolidation tests.

15. Powder Components Argonne novel phosphate binder Class C fly ash Boric acid (% binder) OPC (Type I) 24-h compressive strength (psi) 50 3.750823 50403.7510756 Composition and compressive strength of sample mixed in the Consistometer: Compressive strength values are slightly lower than those found in consolidation tests due to oil contamination during the consistency test.

16. Consistency graph without Portland cement

17. Consistency graph with 10% Portland cement

18. Project Schedule: Completed tasks: Task 1 Literature search. Task 2 Optimization of sealants and Testing for niche applications  Evaluation of pumping characteristics, physical and mechanical properties  Optimization of thermal properties  Bonding Characteristics  Formulation in presence of down-hole gases Remaining Tasks (Tasks for next quarter): Task 4 laboratory tests at ANL, regarding flash setting of mixture of Ceramicerete(95%) and Portland cement(5%) followed by tests at BJ Task 3-A Economics of oil well cementing Task 3-B Determination of thawed-permafrost zone and temperature profile in thawed region.