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NOVEL CHEMICALLY BONDED PHOSPHATE CERAMIC BOREHOLE SEALANTS FOR ARCTIC ENVIRONMENT Presented By : Nilesh Limaye, UAF. Principal Investigator : Shirish Patil, UAF. Partner Principal Investigator : Arun Wagh, ANL. Industrial Participant : Jeff Dawson, BJ services.
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NOVEL CHEMICALLY BONDED PHOSPHATE CERAMIC BOREHOLE SEALANTS FOR ARCTIC ENVIRONMENT Presented By : Nilesh Limaye, UAF. Principal Investigator : Shirish Patil, UAF. Partner Principal Investigator : Arun Wagh, ANL. Industrial Participant : Jeff Dawson, BJ services. January 23, 2007 Fairbanks, AK.
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”.
Tests done at BJ: Flash setting of Ceramicrete Void spaces
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
Ceramicrete application for Cementing oil wells : • Ceramicrete formulation used : (Banerjee,2005)
Economics of well cementing : • 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.
Consider a typical oil well that is to be drilled at ANS at a depth of 3500 feet. • Typical oil well configuration at ANS:
Dia.20” Dia.26” Surface Casing Permafrost zone 1800feet. Casing shoe Intermediate Casing Dia.14” Stable Hydrate Zone 1700 feet Dia.22” Ceramicrete
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 * (Dh2 – Dc2) *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
Thus, Total annular volume for given well =152.34 m3. 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/m3. (Banerjee, 2005) • Amount of Ceramicrete = Density * Volume = 152.34 (m3) * 1900( Kg/m3) = 285.45 MT.
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.
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:
Problems associated with current formulation of Phosphate cement: (@ Tomballmeeting) • Failure in consolidation test. • 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%
Test Results: Compression strength in consolidation tests.
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.
Project Schedule: Completed tasks: Task 1Literature search. Task 2Optimization 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 Task 3-A Economics of oil well cementing Task 3-B Determination of thawed-permafrost zone and temperature profile in thawed region. 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