Air Injection Model

(AIM VERSION 4.1)


The Most Comprehensive Air Injection EOR Screening Technology

A Critical First Step Before Any Laboratory Work, Reservoir Simulation, Or Field Piloting


Belgrave AIM

AIM Overview

AIM Key Features

AIM Computations & Output

AIM Internal Correlations

AIM Oil Displacement Models

Two validated oil displacement models (ODM) based on the burned volume approach.

1. Stanford University Petroleum Research Institute (SUPRI) Empirical Model

2. Belgrave Oil and Gas Corp (BOGC) Mechanistic Model

AIM Empirical Model

Oil displacement calculations are based on the oil-recovery/volume-burned method. The method uses curves bluased on field data as well as combustion tube tests for dry combustion.

An additional correlation allows the prediction of volume of reservoir burned before first oil appears, if a gas saturation exists.

The published polynomial for the deviation (curvature) is problematic. The cumulative oil function is not monotonic at low gas saturation and high burned volume. AIM's implementation has addressed this issue.



Reference
An Algorithm for Computing In-Situ Combustion Oil Recovery Performance, SUPRI TR-25, DOE/ET/12056-25 (DE81030340), October 1981.

AIM Mechanistic Model

Belgrave Oil and Gas Corp

This model predicts the performance of both dry and wet combustion and provides mechanistic insight regarding the oil displacement.

Theoretical Air Injection Model

At any given time, oil displace due to the gas flood, steam zone, burned region, and under-riding hot-water flood are considered.

Residual oil saturations in the gas-flood, steam and hot-water zones are part of the input controls. The model predicts arrival time of the steam bank, and facilitates economic analysis of the efficacy of continued oil production after steam breakthrough.

AIM Oil Displacement Models

SUPRI vs. BOGC Oil Production Rate Profiles

SUPRI Empirical Model vs BOGC Mechanistic Model

AIM Mechanistic Model

Heated Volume Temperature Distribution

Dry Combustion vs Normal Wet Combustion

AIM Air Injection Rate Schedules

Nelson & McNeil

Belgrave Oil and Gas Corp.

User inputted/default minimum air flux provides confirmation on adequacy of air injection plateau rate.

AIM Input Data

Reservoir and Operational

General Pool
INPUT DATA UNITS DATA REQUIRMENTS USER
INPUTTED
CALCULATED
DEFAULTS
DEFAULTS ROCK & FLUID PROPERTIES        
         
   Reservoir Depth ft Required 2,500  
   Reservoir Pressure psia Default Available Default 556 psia
   Reservoir Temperature oF Default Available 90.0  
   Total Net Pay Thickness ft Required 50.0  
   Number of Pay Zones   Required 1  
   Reservoir Absolute Permeability md Required 500.0  
   Reservoir Porosity Fraction Required 0.30  
   Current Reservoir Oil Saturation Fraction Required 0.40  
   Current Reservoir Water Saturation Fraction Required 0.60  
   Oil Gravity oAPI Required 18.0  
   Dead Oil Viscosity (at Res.Temp.) cp Options Available BEAL 202.41 cp
   Oil Formation Volume Factor Bbl/STB Default Available Default 1.039 bbl/STB
   Water Formation Volume Factor Bbl/STB Default Available Default 1.003 bbl/STB
         
OPERATIONAL        
         
Current (Non-Air Injection) Projection        
   Areal Extent of Entire Pool Acres Required 640  
   Oil Production Rate STB/day Required 500  
   Oil Production Decline Rate %/yr Required 30%  
   Water Production Rate STB/day Required 300  
   Water Production Decline Rate %/yr Required 15%  
   Water Injection   Required RECYCLING  
Planned Air Injection        
   Investment Delay years Required 2  
   Project Development Area Acres Required 640 OIP = 28,661,657 STB
   Planned Number of Producing Wells in
   Developed Area
  Required 64  
   Planned Ratio of Producers to Injectors   Required 4  
   Pattern Development Schedule No. of Pat./year Required 6  
   Air Injection Rate (per Pattern) MSCF/d Options Provided NELSON & MCNEIL 1,802 MSCF/d
   Water-Air Ratio STB/MSCF Required 0.00 OPT = 0.13 STB/MSCF
   Oil Displacement Model   Options Provided BOGC  
   Areal Sweep Efficiency Fraction Default Available 0.62  
   Vertical Sweep Efficency Fraction Default Available Default Ev = 0.30
   Maximum Cumulative Air-Oil Ratio
  (per Pattern)
MSCF/STB Required 25.0  

AIM Input Data

Financial

General Pool
INPUT DATA UNITS DATA REQUIRMENTS USER
INPUTTED
CALCULATED
DEFAULTS
FINANCIAL        
         
Pool Acquisition Costs        
   Purchase Price $MM Required 16.57  
   Abandonment Liability $MM Required 2.0  
         
Capital Costs        
Air Injection        
Facilities        
   Compression $/hp Required 3000  
   Central Plant Facilities $/STB/d Required 1,500  
   Waste Gas Treating $/MSCF/d Required 150  
   Water Treating, Recycling/Injection,
   Disposal
$/BBL/d Required 250  
   Air Distribution, Vapor recovery, and
  Surface Facilities
$/acre Options Available 8,500  
Wells        
   Drilling, Completion & Equipping of
   New Wells
$/well Required 1,000,000  
   Well Conversion (Producer to Injector
   / Injector to Produer)
$/well Required 400,000  
   No. of New Wells per Pattern   Required 1  
   No. of Conversions per Pattern   Required 1  
   Non- Air Injection        
   Sustain Capital $/STB/yr   1,000  
         
Operating Costs        
Air Injection        
Fixed        
   Well Workovers $/Pattern/year Required 400,000  
   Personnel, Consumables, etc $/year Required 1,000,000  
Variable        
   Compressor Maintenance,
   Instrumentation, Labour
$/MSCF Required 0.15  
   Oil Lifting, Treating, Transportation $/MSCF Required 3.00  
   Water Treating, Recycling/Injection $/STB Required 0.10  

Non- Air Injection

       
Fixed        
   Miscellaneous $/year Required 100,000  
Variable        
   Oil Lifting, Treating, Transportation $/STB Required 3.00  
   Water Treating, Recycling/Injection) $/BBL Required 0.10  
         
Royalties        
Air Injection        
   Royalty before Payout % Required 15.0%  
   Royalty after Payout % Required 15.0%  
Non- Air Injection        
   Conventional Royalty % Required 15.0%  
         
CCA and Taxes        
   Capital Cost Allowance % Required 30.0%  
   Consolidated Corporate Tax Rate % Required 30.0%  
         
Oil Price Forecast        
   Current Oil Price $/BBL Required 60  
   Oil Price Escalation Rate %/year Required 0.0%  

AIM Output

Base Production Economics (Acquisition)

Non- AIR INJECTION FINANCIAL SUMMARY

GENERIC POOL
     
Cumulative Oil Production 506,713 bbl
Cumulative Water Production 592,305 bbl
Cumulative Water Injected 592,305 bbl
     
Acquistion Cost 16.57 MM
Sustaining Capital 1.39 MM
Total Capital 17.96 MM
Abandonment Cost 2.00 MM
     
     
Finding and Development Cost (full cycle) $35.44 /bbl
Project Operation Cost (full cycle) $5.68 /bbl
Recycle Ratio (full cycle, before tax, undiscounted) 1.28  
       
       
  BEFORE TAX
(& ABANDON.)
AFTER TAX
(& ABANDON.)
 
       
Internal Rate of return 10.0% #DIV/0! /year
Profit-Investment-Ratio (undiscounted) 0.26 -0.19  
Cumulative Cash Flow (undiscounted) $5.00 -$3.49 MM
NPV @ 10.0% /year $0.00 -$5.61 MM
NPV@ 15.0% /year -$1.75 -$6.59 MM
       
       
Royalties $4.6 MM    
Taxes $6.5 MM    

AIM Output

Air Injection Pattern Performance

AIM Output

Air Injection Pool Development Performance

Air Injection Pool Development Performance

AIM Output

Incremental Air Injection Economics

AIR INJECTION FINANCIAL SUMMARY

GENERIC POOL
     
Cumulative Oil Production 3,963,907 bbl
Cumulative Air-Oil Ratio 19.23 MSCF/bbl
     
Drilling $16.0 MM
Well Conversions $6.40 MM
Facilities $35.57 MM
Total Capital $57.97 MM
     
     
Finding and Development Cost (full cycle) $14.62 /bbl
Project Operation Cost (full cycle) $20.20 /bbl
Recycle Ratio (full cycle, before tax, undiscounted) 2.11  
       
       
  BEFORE TAX
(& ABANDON.)
AFTER TAX
(& ABANDON.)
 
       
Internal Rate of return 102.4% 63.8% /year
Profit-Investment-Ratio (undiscounted) 1.11 0.72  
Cumulative Cash Flow (undiscounted) $64.13 $41.88 MM
NPV @ 10.0% /year $42.85 $26.06 MM
NPV@ 15.0% /year $35.37 $20.60 MM
       
       
Royalties $35.7   MM
Taxes $22.2   MM

AIM Output

Operational Design

Calculated Parameter Units Value
     
Base Non-Air Production Performance:    
   Oil exponential decline rate /yr 0.356675
   Water exponential decline rate /yr 0.162519
     
Planned Air Injection:    
   Number of Injection Wells (or Patterns)   16
Individual Pattern Performance    
   Pattern Area Acres 40.0
   Pattern Volume Acre-ft 2,000
   Oil-in-Place (per Pattern) MSTB 1,791.4
   Maximum Air Injection Rate (per Pattern) MSCF/d 1,801.7
   Injection Pressure Psia 579.8
   Fracture Pressure Psia 1,750.0
   Compressor Discharge Pressure (per Pattern) Psia 719.7
   Compressor Horsepower Requirement (per Pattern) Hp 449.1
Overall Project Peak Values:    
   Horsepower Requirement Hp 7,186
   Oil Production Rate STB/d 2,514
   Waste Gas Produciton Rate MSCF/d 26,054
   Water Production Rate STB/d 3,554
   Water Injection Rate STB/d 0
Combustion Process    
   Maximum Pattern Size for Sustained Combustion Acres 388.3
   Air Requirement MSCF/ft3 Rock 0.2941
   Oil Burned as Fuel STB/Acre-ft 229.2
   Water Generated by Combustion STB/Acre-ft 186.9
   Spontaneous Ignition Time days 122.6
   Combustion Temperature oF 1,248.4
   Steam Plateau Temperature oF 287.9
     
Consolidated:    
   Pool Life Years 13

AIM Output

Consolidated Operational Performance

Air Injection Consolidated Operational Performance

AIM Output

Consolidated Economics

CONSOLIDATED FINANCIAL SUMMARY

GENERIC POOL
     
Pool Life 13 years
Cumulative Oil Production 4,285,032 bbl
Cumulative Water Production 9,643,569 bbl
Cumulative Air Injected 76,208,560 MSCF
Cumulative Water Injected 248,124 bbl
     
     
Acquisition Cost 16.57 MM
Sustain Capital 0.88 MM
Drilling 16.00 MM
Well Conversions 6.40 MM
Facilities 35,57 MM
Total Capital 75.42 MM
     
Abandonment Cost 2.00 MM
     
     
Finding and Development Cost (full cycle) $17.60 /bbl
Project Operation Cost (full cycle) $18.98 /bbl
Recycle Ratio (full cycle, before tax, undiscounted) 1.82  
       
       
  BEFORE TAX
(& ABANDON.)
AFTER TAX
(& ABANDON.)
 
       
Internal Rate of return 37.8% 22.3% /year
Profit-Investment-Ratio (undiscounted) 0.82 0.44  
Cumulative Cash Flow (undiscounted) $61.78 $33.14 MM
NPV @ 10.0% /year $30.92 $12.73 MM
NPV@ 15.0% /year $21.40 $6.43 MM
       
       
Royalties $38.6   MM
Taxes $26.6   MM

AIM Output

Consolidated Financial Performance

Consolidated Financial Performance 4.1