multiphase pumps in heavy oil production (1)

8/11/2019 Multiphase Pumps in Heavy Oil Production (1)

1/14PAGES 196 // 197

Introduction / Overview

Multiphase Pumps (MPP) are at the heart of thisExtra-Heavy Crude Oil (EHCO) Projects operation

Both, the operating environment and the relativeyouth of this technology have presented challengesto establishing reliable, cost effective operations.

Multiphase Pumps

in Heavy Oil ProductionLessons learned

Luigi Bortolin, Consultant


2/14

2ND INTERNATIONAL EMBT CONFERENCE // MULTIPHASE PUMPS IN HEAVY OIL PRODUCTION LESSONS LEARNED

Reservoir Characteristics

Introduction

Porosity 32 %Avg. Permeability 11.600 md

Oil Viscosity 2.000 cpOil Mobility 6 md/cp

Oil Gravity 9 APIPressure 775 psiTemperature 120 F

Heavy Foamy Oil

We normally dont worry about 3-10%

shrinkage, but this crude may have 50%,not by mass but by fluff

1.5 Bill. bls (35 years)

Reservoir OIP 1.4 Tril. bls EHCO

Oil Mobility 6 md/cp

Outline

Introduction to Project

Solids Impact / Separation

Gas Separation

Performance Monitoring & Diagnosis

Wrap-Up / Lessons Summary


3/14PAGES 198 // 199

MPP Decision Drivers

Eliminate high capital cost of remote flow-stations

Reduce operations manpower and hopefully OPEX

Reduce back pressure on production wells

(increases ultimate recovery late in field life)

Eliminate annular gas gathering along with associated

condensate problems

Facilitate 2-stage separation at the CS to reduce gas

compression requirements

Make the field development plan more flexible

Fuel Coke

The Process

UPGRADERExtra Heavy Crude

Production Facilities

Heavy Syncrude

Light Syncrude

Diluted Oil Pipeline

Diluent Pipeline

Syncrude

LPG

Sulfur

To a foreign

Refinery Gas Oil

To a local

RefineryTo local

Customer


4/14

MPFM

Test System

Gathering

System

Multiphase Pump

Central Station

Diluent

Distribution

System

Diluent

Injection

Skid

Typical Cluster with MPP

Clusters layout and MPPs

CS



5/14PAGES 200 // 201

What wasFound

High Percentage of Oil in Place

in Thinner Sands

How good are

the Junctions?

Multilateral

Solids Impact/Separation

The Source What wasExpected

High Percentage of Oil in Placein Thick Sands

Single Lateral


6/14

Living w/solids

- Solids are an area of concern, have impacted operatingcosts and the potential to cause significant flow restrictions

- MPPs are an early indicator of solids production

- Limited success in preventing solids at the surface

- Hardening is part of the answer, but not 100%

- Pilot test to remove specific grain-size, high wear solids

(long-term bulk solids removal is needed)

Issue: Wear Rate / Long Term Operating Costs

Pass, Push or Crush

Issue: Wear Rate / Long Term Operating Costs

Three ways for Solids to pass an MPP:

Pass fine solids (now its a processing problem)

Push larger solids (now its a pipeline problem)

Gap sized solids Roll & Crush at leading edge of Screw(now its an MPP problem)



7/14PAGES 202 // 203

Tested several sand cyclone systems for construction of a

pilot solids removal facility ( to eliminate solids impairing

MPP performance - not bulk solids removal )

Inlet

Overflow

Underflow

Solids removal test

50 micron and below solids appear to adhere to the crude

and pass through the MPP with nominal impact Particles between 100 and 350 microns create abrasive and

erosive effects

Particles above 350 microns are rolled and crushed at the

leading edge of the screw causing rapid loss of performance

Solids removal was targeted at particles > 100 microns

Sand Removal Test6" Cyclone

0.005.00

10.0015.00

20.0025.00

30.0035.00

3360

2000

800

594

420

300

177

150

44 -

Microns

%byweightoftotal

sample


8/14

Years

Gas separation

Oil & Gas production history

GOR 130

cf/bbl

GOR 465

cf/bbl

Solids Removal Pilot

Pilot test successfully removed high wear grain-size solids



9/14PAGES 204 // 205

160160

MBOEPDMBOEPD

3939

MBOEPDMBOEPD

EHCOEHCO

25% of25% of

CapacityCapacity

5454

MBOEPDMBOEPD

3939

MMBOEPDBOEPD

106MBOE Liquid capacity yields 4.7MMSCFD Gas capacity106MBOE Liquid capacity yields 4.7MMSCFD Gas capacity

Effect of Gas Volume Factor

Pass or Bypass

Issue: Wear Rate / Lost Capacity / CAPEX / OPEX

Impact:

Pumps are positive displacement and Gas steals a large

fraction of capacity

Slugging / Blowby effects

Impact on bearing and case temperatures


10/14

Performance & Diagnostics

Issue: Managing Wear Rates and Field Performance

Early detection of abnormal operating conditions are critical

to managing MPP operting costs

Linking MPP performance to other process information has

synergistic benefits.

Pre-separation at MPP suction

MPFM

Test System

Gathering

System

MultiphasePump

Central

Station

Diluent

Distribution

System

Diluent

Injection

Skid

Gas

Extraction

Increase in EHCO Production



11/14PAGES 206 // 207

Other Diagnostics/Observations

Multiphase Pump performance variables can act as a check meter to

multiphase meters for well testing. The systems complement one

another

Actual vs. Calculated Power (Kw)

Kw

0

100

200

300

400

500

600

700

800

900

1000

Location

Tied to RPM and Gas, a good indicator

of lost capacity.

Condition and process monitoring should be an essential part of

the design

Actual vs. Calculated rpm

0

200

400

600

800

1000

1200

1400

1600

1800

2000

Location

rpm

Good indication of wear and increased

gap between the screw and linerThe difference between the bearing and the discharge

temperature is normally in a range from 40 to 90F.

A deviation will mean a low rate of diluent flushing

In&Out-Bearings, Casing and Discharge Temperatures

0.00

25.00

50.00

75.00

100.00

125.00

150.00

175.00

200.00

225.00

250.00

time

F

Discharge Temp. (F)Casing Temp. (F)

Inbearing Temp. (F)

OutBearing Temp. (F)Difference


12/14

Wrap-Up / Lessons summary

Top Ten Failures by Class by Cost (One year)

52%

73%

78%

82%

100%98%

95%93%

89%

86%

1 2 3 4 5 6 7 8 9 10

MPPs Solids & Gas

Heat

ExchangersSolids

Submergible

Well pumps

Costs

Due to exposed pipelines, large fluctuations in temperature and

pressures are seen between night/day. This complicates long term

trending (variations up to 40 F)



13/14PAGES 208 // 209

Reduce gas lock effects by improving piping design for

gathering system( routing to reduced undulations in flowline )

Maintenance is going to be high, but likely still lower than

a stand-alone flow station

( quick turn-around key to Uptime )

Structural design critical for vibration control

( foundation and inlet/outlet piping )

MPP Lessons learned

Design modifications

Hard-Hard faces on Bearings and relocated throttle bushings to

make more resistant to solids

Modification to Bearing types & extended Shaft landing area

Diluent injection at the suction of the MPP to counteract gas

slugging

Change in maintenance philosophy. Rapid change-outs of

screws and liners

Future Ultra-hardened screws/liners

Integration of solids removal with Gas removal systems


14/14

Eliminate high capital cost of remote flow-stations

Reduce operations manpower and hopefully OPEX

Reduce back pressure on production wells

(increases ultimate recovery late in field life)

Eliminate annular gas gathering along with associated

condensate problems

Facilitate 2-stage separation at the CS to reduce gas

compression requirements

Make the field development plan more flexible

MPP Decision Drivers

Reduce

(not w/o Gas handling)

Deffer

(higher GOR & sooner)

?

X

X


multiphase pumps in heavy oil production (1)

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