Well Performance

ENHANCING WELL PERFORMANCE

Edmond NGALEMO

PETROM TECH DAY, SEP 07

AGENDA

� WELL PERFORMANCE

� WELL PROBLEMS

� WELL PERFORMANCE EVALUATION

� PRODUCTION LOGGING

� OPTIONS FOR ENHANCEMENT

WELL PERFORMANCE

� FACTORS EFFECTING WELL PERFORMANCE • RESERVOIR STRUCTURE

• DRIVE MECHANISM

• COMPLETION SYSTEM

RESERVOIR RECOVERY COMPLETION

WELL PROBLEMS

WELL PROBLEMS

WELL PROBLEMS

WELL PERFORMANCE EVALUATION

� RESERVOIR• Hydrocarbon – water contact

• Detect thief zone

• Well test

� WELL INTEGRITY• Mechanical problems

• Channeled cement

� COMPLETION• Zonal contribution (injection, production)

• Water breakthrough, coning

• Treatment effectiveness

PRODUCTION LOGGING

PL MEASUREMENTS

� TEMPERATURE

� PRESSURE

� TUBING/CASING SIZE

� FLOW DISTRIBUTION• RATE

• HOLD UP

PRODUCTION LOGGING PROVIDES DETAILED INFORMATION ON THE NATURE

AND BEHAVIOR OF FLUIDS IN THE WELL DURING PRODUCTION OR INJECTION.

PL SERVICES� Thermometer

� Manometer (sapphire gauge, quartz gauge)

� Fluid density (gradiomanometer, nuclear)

� Flowmeters (continuous, fullbore)

� FloView (digital fluid entry tool)

� GHOST (Gas holdup optical sensor tool)

� FSI (floscan imager)

� Gamma Ray

� CCL

� Noise (single frequency, multiple frequency)

� Caliper

� Radioactive tracer

� Water flow logging

� Gravel pack logging

� Three-phase holdup

� Downhole video

PFCS SPINNER,

ELECTRICAL PROBES

GHOSTOPTICAL PROBES

PGMCGRADIO-MANOMETER

PILSINLINE SPINNER

PBMSGR, CCL, Temp, Press

SWRS ROLLER

SWBS WEIGHT

THERMOMETER

� PRINCIPLE OF OPERATION

• Platinum temperature resistor

� First log down 1800 ft/hr

� SPECIFICATIONS

• Range: – 25 °C to 150 °C

• Resolution: 0.006 °C

• Accuracy: ± 1 °C

TEMPERATURE

APPLICATIONS

� LOCATION OF FLUID ENTRIES

� DETERMINATION OF FLOW BEHIND PIPE

� DETECTION OF GAS PRODUCTION

� QUALITATIVE EVALUATION OF FLUID FLOW

� DOWNHOLE TEMPERATURE INFORMATION

� EVALUATION OF FRACTURE TREATMENTS

� EVALUATION OF MECHANICAL INTEGRITY OF A COMPLETION

TYPICAL TEMPERATURE LOG

DISTRIBUTED TEMPEATURE SENSOR� RealRealRealReal----time monitoring of temperaturetime monitoring of temperaturetime monitoring of temperaturetime monitoring of temperature

• Continuous data without well intervention.• Sensor: fiber optic technology• real-time transmission of downhole data

� Faster, better decisionsFaster, better decisionsFaster, better decisionsFaster, better decisions• water / gas breakthrough, steam management • zonal isolation, well integrity• injection monitoring, artificial lift performance

� Reduced operating costsReduced operating costsReduced operating costsReduced operating costs• minimizing the need for production logs • minimizing production losses

� SpecificationsSpecificationsSpecificationsSpecifications

Depth: up to 30 km

Sensing length: 12 km

Sample spacing: 1 m

Temp/Press: 150oC / 10 kpsi

Resolution: 0.05 degC

� Not suitable for all wells Not suitable for all wells Not suitable for all wells Not suitable for all wells (Resolution)

PRESSURE GAUGES

SENSORS

� STRAIN GAUGE

– PAINE

– SAPPHIRE

� QUARTZ GAUGE

– CONVENTIONAL

– COMPENSATED

ELECTRONICS

� ACQUISITION FREQUENCY

– FAST GAUGES

– SLOW GAUGES

� RESOLUTION

� NOISE

QUARTZ

STRAIN

ACCURACY, RESOLUTION, REPEATABILITY

SENSITIVITY, TRANSIENT RESPONSE (STABILIZATION)

Pre

ssu

re (

psi

a)

PRESSURE GAUGE Specification

� ACCURACY• Difference between a measured value and the true value obtained from a

reference standard.

� RESOLUTION• Minimum pressure change that is detected by the gauge.

� REPEATABILITY• Maximum difference between measurements of the same pressure.

� SENSITIVITY• Ratio of the induced variation in the transducer output to the change in

applied pressure.

� TRANSIENT RESPONSES TO TEMPERATURE VARIATIONS

� TRANSIENT RESPONSES TO PRESSURE VARIATIONS

PRESSURE GAUGES

SpecificationSpecificationSpecificationSpecification CQG Quartz Gauge CQG Quartz Gauge CQG Quartz Gauge CQG Quartz Gauge Sapphire GaugeSapphire GaugeSapphire GaugeSapphire Gauge PSOI (differential)PSOI (differential)PSOI (differential)PSOI (differential)

AccuracyAccuracyAccuracyAccuracy 2.0 psi + 0.01% of reading 2.0 psi + 0.01% of reading 2.0 psi + 0.01% of reading 2.0 psi + 0.01% of reading ± 5 psi + 0.01% of reading ± 5 psi + 0.01% of reading ± 5 psi + 0.01% of reading ± 5 psi + 0.01% of reading ± 0.015 psi ± 0.015 psi ± 0.015 psi ± 0.015 psi

RepeatabilityRepeatabilityRepeatabilityRepeatability 1.0 psi 1.0 psi 1.0 psi 1.0 psi

ResolutionResolutionResolutionResolution 0.01 psi at 1Hz0.01 psi at 1Hz0.01 psi at 1Hz0.01 psi at 1Hz 0.05 psi at 1Hz0.05 psi at 1Hz0.05 psi at 1Hz0.05 psi at 1Hz

Temperature ratingTemperature ratingTemperature ratingTemperature rating 302°F (150°C) 302°F (150°C) 302°F (150°C) 302°F (150°C) 302°F (150°C) 302°F (150°C) 302°F (150°C) 302°F (150°C) 302°F (150°C) 302°F (150°C) 302°F (150°C) 302°F (150°C)

Pressure ratingPressure ratingPressure ratingPressure rating 15 kpsi15 kpsi15 kpsi15 kpsi 10 kpsi10 kpsi10 kpsi10 kpsi ± 20 psi± 20 psi± 20 psi± 20 psi

PRESSURE

APPLICATIONS

� DOWNHOLE PRESSURE INFORMATION for PVT evaluations• Fluid compression – shrinkage

• GOR

• Downhole to Surface / Surface to Downhole conversions

� DERIVE FLUID DENSITY

� RESERVOIR CHARACTERISTICS from pressure transient analysis

• permeability(k)

• permeability thickness (kh),

• formation skin factor (s)

• reservoir extent and boundaries

• productivity index

• absolute open flow potential (AOFP, see glossary).

SPINNER FLOWMETER

PRINCIPLE OF OPERATION

� IMPELLER ROTATES AS FLUID MOVES

� ROTATIONAL SPEED IS MEASURED ELECTRICALLY (RPS)

� FLUID FLOW DERIVED FROM CALIBRATION OF RPS

APPLICATONS

� QUANTITATIVE FLUID MOVEMENT WITHIN THE WELL ON A ZONE-

BY-ZONE BASIS.

Coils

Spinnerblades

Magnet

SPINNER FLOWMETER

SPECIFICATIONS

150150150150150150150150Temperature (Temperature (Temperature (Temperature (°C)

57, 89, 127, 17857, 89, 127, 17857, 89, 127, 17857, 89, 127, 17830, 42, 6130, 42, 6130, 42, 6130, 42, 61Spinner diameter (mm)Spinner diameter (mm)Spinner diameter (mm)Spinner diameter (mm)

200200200200400400400400Minimum flow rate (B/D)Minimum flow rate (B/D)Minimum flow rate (B/D)Minimum flow rate (B/D)(1)(1)(1)(1)

2000020000200002000015000150001500015000Pressure (psi)Pressure (psi)Pressure (psi)Pressure (psi)

1 11/161 11/161 11/161 11/161 11/16, 2 1/8, 2 7/81 11/16, 2 1/8, 2 7/81 11/16, 2 1/8, 2 7/81 11/16, 2 1/8, 2 7/8Tool diameter in tubing (in)Tool diameter in tubing (in)Tool diameter in tubing (in)Tool diameter in tubing (in)

FullboreFullboreFullboreFullboreContinuousContinuousContinuousContinuousFlowmetersFlowmetersFlowmetersFlowmeters

(1) (7-in. casing) Minimum flow rates correspond to single-phase flow. Minimum flow

rates for multiphase flow vary according to the fluid properties of the mixture.

SPINNER CALIBRATION

- 0 +Cable Speed

- 0 +RPS

E

D

C

B

A

InInInIn----Situ Situ Situ Situ FlowmeterFlowmeterFlowmeterFlowmeter Calibration PlotCalibration PlotCalibration PlotCalibration Plot

Cable Speed

DownUp

RPS

ym

Vt

A

B

C

D

E

y=mx+c

x=(1/m)y+d

V=(1/m)RPS+Vt

Vm = ( RPS / Slope ) + Vt – CS

Vm = ( RPS . PitchPitchPitchPitch ) + Vt – CS

SPINNER – MIXTURE APPARENT VELOCITY

turbulent laminar

GRADIOMANOMETER FLUID DENSITY TOOL


g h cosθ∆P

+ ρsoρf =

FACTORS AFFECTING GRADIOFACTORS AFFECTING GRADIOFACTORS AFFECTING GRADIOFACTORS AFFECTING GRADIO

�TOOL MOTION

�KINETIC

�JETTING

�FRICTION

GRADIOMANOMETER

SPECIFICATIONS

YesDST and TCP resistanceDST and TCP resistanceDST and TCP resistanceDST and TCP resistance

(1)(1)(1)(1)Including P&T hysteresis, fitting error and repeatability

Class 6 (500 g/2 ms)Shocks and vibrations Shocks and vibrations Shocks and vibrations Shocks and vibrations (3)(3)(3)(3)

40 psiBurst pressureBurst pressureBurst pressureBurst pressure

0.015 psi (1)(1)(1)(1)AccuracyAccuracyAccuracyAccuracy

± 20 psiOverpressure without Overpressure without Overpressure without Overpressure without decalibrationdecalibrationdecalibrationdecalibration

175°CTemperature rangeTemperature rangeTemperature rangeTemperature range

SchlumbergerManufacturerManufacturerManufacturerManufacturer

PSOIPSOIPSOIPSOIDifferential pressure transducersDifferential pressure transducersDifferential pressure transducersDifferential pressure transducers

GRADIOMANOMETER

PGMC SPECIFICATIONS

0 to 2 g/ccRange

0.002 g/ccResolution

± 0.04 g/cc (below 20 deviation)Accuracy

GRADIOMANOMETER

APPLICATIONS

� DETERMINE FLUID HOLD UP• FROM AVERAGE DENSITY

� DETECT ENTRY POINTS

LIMITATIONS

� DEVIATED WELLS

� FLUID LAYERING

� LOW CONTRAST BETWEEN FLUID

ELECTRICAL PROBES


Probe sensitive to Probe sensitive to Probe sensitive to Probe sensitive to fluid conductivityfluid conductivityfluid conductivityfluid conductivity

Output is binaryOutput is binaryOutput is binaryOutput is binary

Water holdup

Hw = White time / Total TimeHw = White time / Total TimeHw = White time / Total TimeHw = White time / Total Time

Hydrocarbon Holdup

HhHhHhHh = 1 = 1 = 1 = 1 –––– HwHwHwHw

Bubble count

BBC = Σ bubbles /second

ELECTRICAL PROBES

PFCS SPECIFICATIONS

1,000 ppm @ 100degC

2,000 ppm @ 25 degC …. Charts

Minimum water salinity

2 m/s (telemetry), 1m/s (memory)Maximum fluid velocity

10% for bubble size > 1mmBubble Count

5 % water (2% when Yw>90) Accuracy

ELECTRICAL PROBES

APPLICATIONS

� LOCATING FIRST OIL/WATER ENTRIES, WITH HIGH RESOLUTION

� WATER HOLDUP MEASUREMENT ⇒ FLOW RATE COMPUTATION

FLOVIEW LOG

Stratified flow in

horizontal well

First oil entry

OPTICAL PROBES


Probe sensitive to Probe sensitive to Probe sensitive to Probe sensitive to fluid refractive indexfluid refractive indexfluid refractive indexfluid refractive index

Output is binaryOutput is binaryOutput is binaryOutput is binary

Gas holdup

Hg = Black time / Total TimeHg = Black time / Total TimeHg = Black time / Total TimeHg = Black time / Total Time

Liquid Holdup

HHHHLiquidLiquidLiquidLiquid = 1 = 1 = 1 = 1 –––– HgHgHgHg

Bubble count

BBC = Σ bubbles /second

Incident light (Ii) ((((IrIrIrIr)))) Reflected light

Ir/Ii ?

OPTICAL PROBES

GHOST SPECIFICATIONS

8 m/s (covers most of velocity ranges)Maximum fluid velocity

1% for Bubble size > 0.002 in or 0.1mmBubble Count

7% standard probe

5% probes without protectors

1 % If Yg > 98 % or < 2 %

Accuracy

OPTICAL PROBES

APPLICATIONS

� LOCATE FIRST GAS/LIQUID ENTRIES, WITH HIGH RESOLUTION

� GAS HOLDUP MEASUREMENT ⇒ FLOW RATE COMPUTATION

FLOVIEW – GHOST LOG

GR

� CORRELATION

• Depth matching between separate trips in

the well.

• Providing the depth control needed for cased

hole operation

� IDENTIFICATION OF RADIOACTIVE ZONES

(SCALES) IN PRODUCING WELL

CCL

� CORRELATION IN CASED HOLE

Operates in ferromagnetic pipes

PIPE CCL

MULTIPHASE FLOW

FLOWRATE-VELOCITIES-HOLDUP-CUT

Holdup Holdup Holdup Holdup YwYwYwYw + + + + YoYoYoYo = 1= 1= 1= 1

FlowratesFlowratesFlowratesFlowrates QwQwQwQw = = = = YwYwYwYw * * * * VwVwVwVw * Area* Area* Area* Area

QoQoQoQo = = = = YoYoYoYo * Vo * Area* Vo * Area* Vo * Area* Vo * Area

QtotQtotQtotQtot = = = = QwQwQwQw + + + + QoQoQoQo

Slippage VelocitySlippage VelocitySlippage VelocitySlippage Velocity Vs = Vo Vs = Vo Vs = Vo Vs = Vo ---- VwVwVwVw

Superficial Velocity Superficial Velocity Superficial Velocity Superficial Velocity VsupoilVsupoilVsupoilVsupoil= = = = QoQoQoQo / Area/ Area/ Area/ Area

VsupwaterVsupwaterVsupwaterVsupwater = = = = QwQwQwQw / Area/ Area/ Area/ Area

Mixture VelocityMixture VelocityMixture VelocityMixture Velocity VmixVmixVmixVmix = = = = QtotQtotQtotQtot / Area/ Area/ Area/ Area

VmixVmixVmixVmix = = = = ΣΣΣΣ VsupVsupVsupVsup

Water CutWater CutWater CutWater Cut BS&W = BS&W = BS&W = BS&W = QwQwQwQw / / / / QtotQtotQtotQtot

YoYw

VoVw

OPTIONS FOR ENHANCEMENT

� WATER SHUT OFF

� SQUEEZE JOBS

� TUBING / CASING PATCHES

� HYDRAULIC FRACTURING

� MATRIX ACIDIZING

� SAND CONTROL

� PERFORATING - REPERFORATION

� MULTIPLE COMPLETIONS

� ARTIFICIAL LIFT

THROUGH TUBING CEMENT PLUGS

TOTEA EXAMPLE – PRODUCTION LOG

WELL PERFORMANCE

THANKS

MANOMETER

� PRINCIPLE OF OPERATION• Force summing device

� GAUGES• Paine gauge

• Sapphire gauge

• Hewlett-Packard gauge

• QuartzdyneTM gauge

• Compensated quartz gauge

Documents

Well Performance