NOVEL CHEMICALLY BONDED NOVEL CHEMICALLY BONDED PHOSPHATEPHOSPHATE

CERAMIC BOREHOLE SEALANTS FOR CERAMIC BOREHOLE SEALANTS FOR

ARCTIC ENVIRONMENT ARCTIC ENVIRONMENT

Presented ByPresented By : Nilesh Limaye, UAF. : Nilesh Limaye, UAF.

Principal InvestigatorPrincipal Investigator : Shirish Patil, UAF. : Shirish Patil, UAF. Partner Principal InvestigatorPartner Principal Investigator : Arun Wagh, : Arun Wagh,

ANL.ANL. Industrial ParticipantIndustrial Participant : Jeff Dawson, BJ : Jeff Dawson, BJ

services. services.

January 23, 2007January 23, 2007

Fairbanks, AK.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)

Ceramicrete Formulation

Weight %

MgO 25%

KH2PO4 27.20%

C-Class fly Ash 10.20%

Wollastonite 10.20%

Boric Acid 0.09%

Water 27.20%

Total 100%

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.

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 3500 Ft.

Permafrost Zone 1800 Ft.

Stable Hydrate Zone 1700 Ft.

Diameter Size

open hole in permafrost Zone 26’’

Surface Casing in permafrost Zone

20’’

hydrate zone 22’’

intermediate casing 14’’

Permafrost zone1800 feet.

Stable Hydrate Zone1700 feet

Ceramicrete

Dia.20”

Dia.26”

Dia.14”

Dia.22”

Surface Casing

Casing shoe

Intermediate Casing

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.Ceramicrete Formulation:

Weight %  

Tones $

MgO 25% 0.25 76.9538,475.0

0

KH2PO4 27.20% 0.272 83.72115,906.

10

C-Class fly Ash 10.20% 0.102 31.39 784.89

Wollastonite 10.20% 0.102 31.3918,837.3

6

Boric Acid 0.09%0.000

90.2770

2 218.29

Water 27.20% 0.273 84.02  

Total 100% 1.00308.2

8174,221

.64

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 ($)

1 308.28 174,221.64

10 3,078.00 1,853,910.79

20 6,156 3,695,505.28

30 9234.00 5,528,413.39

40 12,312.00 7,364,041.12

50 15,390.00 9,199,193.36

60 17,100.00 10,217,638.26

70 19,950.00 11,911,844.45

80 24,621.53 14,701,080.44

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%

 

Powder Components 

 

24-h compressive strength 

Argonne's novel phosphate Binder 

Class C fly ash 

Boric acid(% binder)

OPC(Type I)

50 50 3.75 0 1024

40 50 3.75 10 657

40 50 2.5 10 657

45 45 3.75 10 657

50 40 3.75 10 1052

Test Results:

Compression strength in consolidation tests.

Powder Component

s       

Argonne novel

phosphate binder

Class C fly ash

Boric acid (%

binder)

OPC(Type

I)

24-h compressive strength (psi)

50 50 3.75 0 823

50 40 3.75 10 756

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.

Consistency graph without Portland

cement

Consistency graph with 10% Portland

cement

Project Schedule:Completed tasks:

Task 1 Literature search.

Task 2 Optimization of sealants and Testing for niche applicationsEvaluation 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.