Welcome

MAHAVIR SINGH

M.Tech. (Applied Geophysics)-III, IIT –Roorkee

Email: mstomar84@gmail.com

Production OptimizationProduction Optimization

Overview Overview -- IntroductionIntroduction

-- Definition of Production Definition of Production OptimizationOptimization

-- Major challengesMajor challenges

-- Productive formationProductive formation

-- Reservoir DrivesReservoir Drives

-- Oil Recovery MechanismOil Recovery Mechanism

-- EOR TechniquesEOR Techniques

-- World Oil ScenarioWorld Oil Scenario

-- Optimal ManagementOptimal Management

-- ConclusionConclusion

IntroductionIntroduction

Production mangers always try to enhance their asset;Production mangers always try to enhance their asset;

In short term, they must increase:In short term, they must increase:- - hydrocarbon delivery and hydrocarbon delivery and - - reduce operation costs reduce operation costs

In long term, they must increase In long term, they must increase - - reservoir recovery factor reservoir recovery factor - - decrease capital expendituredecrease capital expenditure- - maximize productionmaximize production- - to improve well performanceto improve well performance- - Enhance Oil Recovery (EOR)Enhance Oil Recovery (EOR)- - increase Net Present Value (NPV)increase Net Present Value (NPV)

Def. of Production OptimizationDef. of Production Optimization

Development of hydrocarbon reservoirs Development of hydrocarbon reservoirs - - on a Field and well basison a Field and well basis

To enable To enable - - maximum sustained production ratesmaximum sustained production rates- - at the lowest possible costat the lowest possible cost

In order toIn order to- - provide the greatest NPV (Net Present Value)provide the greatest NPV (Net Present Value)- - in safe and environmentally responsible mannerin safe and environmentally responsible manner- - while harvesting the hydrocarbon asset to the while harvesting the hydrocarbon asset to the fullest extent possible.fullest extent possible.

Major challenges during Major challenges during productionproduction

- - equipment failureequipment failure

- - wellbore problemwellbore problem

-- saltwater disposal saltwater disposal

- - reduction in permeabilityreduction in permeability

- - pressure gradientpressure gradient

- - structural uncertainty in subsurfacestructural uncertainty in subsurface

- - oil migration (seepage or leakage)oil migration (seepage or leakage)

Productive FormationsProductive Formations

The earth's crust is composed of : The earth's crust is composed of :

-- igneousigneous

-- metamorphicmetamorphic

-- sedimentarysedimentary

Oil and Gas are found in all three kinds of rock, Oil and Gas are found in all three kinds of rock,

most closely they are associated with sedimentary rocks;most closely they are associated with sedimentary rocks;

Sedimentary materials can be classified as Sedimentary materials can be classified as

-- rocks (sandstone, shale)rocks (sandstone, shale)

-- carbonates (lime stones)carbonates (lime stones)

-- dolomites ( Mgdolomites ( Mg((COCO33))2 2 ))

Oil and Gas moved Oil and Gas moved upward from the lower upward from the lower sea floor source beds into sea floor source beds into the more porous rocks the more porous rocks above; above;

Within the porous layers, Within the porous layers, they continued to move they continued to move upward until they reached upward until they reached a layer of nonporous rock, a layer of nonporous rock, which trapped the fluids;which trapped the fluids;

The non-porous rock which act as a barrier for further oil and gas migration is known as trap;

Source: Forest Gray

Accumulation and Occurrence Accumulation and Occurrence of Hydrocarbonof Hydrocarbon

Source: Forest Gray

The weight of overlying rock layers, compacts the seafloor, squeezing the hydrocarbons out from the source beds and move upward into the reservoir rocks

http://www.ldeo.columbia.edu/edu/dees/U4735/projections/pitman/37.trap.mig.jpg

Resevoir and Oil Migration

Anticline

Impermeable basement

oil

water water

Conditions for productive reservoirConditions for productive reservoir

-- A trap must exist to block the oil and gas;A trap must exist to block the oil and gas;

-- A reservoir must have enough A reservoir must have enough ** thicknessthickness** aerial extent and aerial extent and ** pores space to accumulate of pores space to accumulate of

hydrocarbons;hydrocarbons;** High permeability High permeability

-- It must be able to yield the fluid at a satisfactory rate;It must be able to yield the fluid at a satisfactory rate;

-- It must contain enough fluids to make the entire It must contain enough fluids to make the entire venture commercially worthwhile;venture commercially worthwhile;

Reservoir Drives Reservoir Drives

What creates the driving force that moves the fluids in the What creates the driving force that moves the fluids in the rock to the wellbore? rock to the wellbore?

- - pressure differencepressure difference-- water drivewater drive- - gas cap drivegas cap drive-- gravity drivegravity drive

Gravity drive: gas, oil, and water tend to divide themselves in reservoirs according to their densities;

Source: Forest Gray

Oil Recovery Mechanisms Oil Recovery Mechanisms

-- Oil recovery is a displacement process; Oil recovery is a displacement process;

-- Displacing agents-Displacing agents-** water flooding and water flooding and ** Gas (Gas (COCO22, N, N22 , or natural gas , or natural gas) injection) injection

-- There are basically six Oil driving mechanisms:There are basically six Oil driving mechanisms:** dissolved-gas drivedissolved-gas drive** gas-cap drive gas-cap drive ** water drive water drive ** rock and liquid expansion driverock and liquid expansion drive** gravity drainage drivegravity drainage drive** combination drivecombination drive

Factors Influencing RecoveryFactors Influencing Recovery

Characteristics of the productive formation:Characteristics of the productive formation:-- porosityporosity-- permeability permeability -- connate water content connate water content -- uniformityuniformity-- continuity and continuity and -- structural configurationstructural configuration

Properties of the reservoir oil:Properties of the reservoir oil:-- viscosityviscosity-- shrinkageshrinkage-- quantity of gas in solution;quantity of gas in solution;

Operation controlsOperation controlsPressure behaviorPressure behaviorWell conditions and structural location Well conditions and structural location

Enhance Oil Recovery (EOR)Enhance Oil Recovery (EOR)

Primary recovery:Primary recovery:- - the natural pressure of the reservoir or gravity drive oil into the natural pressure of the reservoir or gravity drive oil into the production wellthe production well- - artificial lift techniques (such as pumps) bring the oil to the artificial lift techniques (such as pumps) bring the oil to the surfacesurface- - primary recovery producing 10% of the original oil in place;primary recovery producing 10% of the original oil in place;

Secondary recovery techniques:Secondary recovery techniques:- - water flooding water flooding -- immiscible gas injection (immiscible gas injection (displace oil, and drive it to a production displace oil, and drive it to a production wellwell))-- producing 20 to 40 % of the original oil in place;producing 20 to 40 % of the original oil in place;

Tertiary, or EOR, techniques:Tertiary, or EOR, techniques:-- chemical flooding (chemical flooding (polymer, surfactant or alkalinepolymer, surfactant or alkaline))-- miscible flooding (miscible flooding (COCO2 2 , natural gas or N, natural gas or N22 ))-- thermal recovery (thermal recovery (add heat to the reservoir to reduce oil viscosityadd heat to the reservoir to reduce oil viscosity))-- producing 30 to 60% or more of the original oil;producing 30 to 60% or more of the original oil;

Water-floodingWater-flooding

The following consideration is taken into account while The following consideration is taken into account while

determining if a reservoir is suited for water-flooding or not:determining if a reservoir is suited for water-flooding or not:

-- Reservoir geometryReservoir geometry

-- LithologyLithology

-- Reservoir DepthReservoir Depth

-- PorosityPorosity

-- PermeabilityPermeability

-- Continuity of rock propertiesContinuity of rock properties

-- Magnitude and Distribution of fluid saturationsMagnitude and Distribution of fluid saturations

-- Relation in fluid properties and relative Relation in fluid properties and relative permeabilitypermeability

COCO22 Injection Injection

-- COCO2 2 EOR involves injecting high pressure COEOR involves injecting high pressure CO22

into into an oil reservoir; an oil reservoir;

-- The productivity of producer wells is enhanced The productivity of producer wells is enhanced and and COCO22 is stored in the oil reservoir; is stored in the oil reservoir;

-- CO2 injection can increases oil recovery by 50%CO2 injection can increases oil recovery by 50%

Source: http://www.seed.slb.com/en/scictr/watch/climate_change/images/eor.jpg

World Oil ScenarioWorld Oil Scenario

-- World without oilWorld without oil

- - Demand is increasing continuously Demand is increasing continuously

-- Continuous decline production rateContinuous decline production rate

Source: www.d-n-i.netfcspdfhirsch_houston_aspo.pdf

Source: www.d-n-i.netfcspdfhirsch_houston_aspo.pdf

Optimal ManagementOptimal Management

-- Use of advance techniquesUse of advance techniques

-- Intelligent production systemsIntelligent production systems

-- Communication systemsCommunication systems

-- Data storage, retrieval & Integration Data storage, retrieval & Integration

-- Uncertainty mappingUncertainty mapping

-- Surface facilities monitoringSurface facilities monitoring

-- Downhole monitoringDownhole monitoring

http://www.bakerhughes.com/investor/resources/pdf/po_analyst.pdf

http://www.bakerhughes.com/investor/resources/pdf/po_analyst.pdf

ConclusionConclusionA multi-disciplinary team approach has been used to implement the process of production optimization using

- Internet computer network- communication links- timely team meetings - corporate database - optimizing the flow and quality of technical data - information to improve performance

Broad and effective portfolio of optimization solutions needs to: - Accelerate production - Increase recovery factors - Reduce operation costs

The manual production optimization approaches are both time consuming error prone due to the complexity and large volume of data that have to be considered

Cont…Cont…

Optimization techniques can :Optimization techniques can :

-- maximize the productionmaximize the production

-- improve well performanceimprove well performance

-- reducing operation costreducing operation cost

-- enhance oil recoveryenhance oil recovery

-- help to achieve ultimate goal help to achieve ultimate goal

(i.e. increasing the asset)(i.e. increasing the asset)

Tertiary or EOR techniques can increases the oil recovery by Tertiary or EOR techniques can increases the oil recovery by

30 to 60% as compared with primary of 10% and secondary 30 to 60% as compared with primary of 10% and secondary

recovery of 20 to 40%.recovery of 20 to 40%.

CO2 injection is an efficient EOR technique which accounts for CO2 injection is an efficient EOR technique which accounts for

nearly 50% recoverynearly 50% recovery

ThankThank you you forfor youryour kind kind attention!attention!