Coal Seam Gas Wellhead Facilities

Some observations & ideas from Australian practice

SPE APPLIED TECHNOLOGY WORKSHOP (ATW)

PRODUCTION MANAGEMENT BEST PRACTICES FOR CBM FIELDS

30 March-2 April 2009 • Queensland, Australia

Geoffrey A . McKee +61 4186 777 51 SPE Member 3190919

Overview. . . .

2 Production Management Best Practices for CBM Fields, SPE Applied Technology Workshop, Queensland, 30 March - 2 April, 2009

What do we mean by “wellhead facilities”?

Design. Where do we start?

Benchmarks. What do other operators do?

Example. One design approach for one project.

Some untested new concepts.

CSG Wellhead Facilities

Definition. What are wellhead facilities?

3 Production Management Best Practices for CBM Fields, SPE Applied Technology Workshop, Queensland, 30 March - 2 April, 2009

Produced water

Produced gas

Mechanical drive for downhole pumps Fuel gas filter and drier Gas and water lines and fittings Gas flow meter (orifice or proprietary) Safety relief valves on gas & water lines Control panel including flow computer

Gathering systemWellhead Wellhead facilities

Produced water

Produced gas

Above ground Below ground

HDPE

HDPE150#

150#

API 3000#

API 3000#

Gas (throttling) control valve? Remotely operated gas shutdown valve? Separator for de-gassing water? Separator for de-watering gas? Separator for co-mingled water and gas?

Possible extra items (if justified):-

Basic system:-

CSG Wellhead Facilities

Real schematic #1 – basic system

4 Production Management Best Practices for CBM Fields, SPE Applied Technology Workshop, Queensland, 30 March - 2 April, 2009

CSG Wellhead Facilities

Real schematic #1. . . . . with separator added for “frothy” water

5 Production Management Best Practices for CBM Fields, SPE Applied Technology Workshop, Queensland, 30 March - 2 April, 2009

CSG Wellhead Facilities

Produced water downholepumps (~300 kPag)

Gas from annulus(140 kPag)

With high water pumping rates: gas drawn into downhole pumps problems with gas separating athigh points in water gathering system

Real schematic #2 - characterised by gas pressure control valve

6 Production Management Best Practices for CBM Fields, SPE Applied Technology Workshop, Queensland, 30 March - 2 April, 2009

CSG Wellhead Facilities

Real schematic #3 – comingled gas + water

7 Production Management Best Practices for CBM Fields, SPE Applied Technology Workshop, Queensland, 30 March - 2 April, 2009

CSG Wellhead Facilities

Design. Where do we start?

8 Production Management Best Practices for CBM Fields, SPE Applied Technology Workshop, Queensland, 30 March - 2 April, 2009

1

• Design Basis Memorandum(DBM)

2• Process Flow Diagram (PFD)

3

• Piping & InstrumentationDiagram (P&ID)

Order equipment only after step 3 is complete!

CSG Wellhead Facilities

Concept schematic – manual gas throttling

9 Production Management Best Practices for CBM Fields, SPE Applied Technology Workshop, Queensland, 30 March - 2 April, 2009

CSG Wellhead Facilities

Concept schematic – remote control

10

Production Management Best Practices for CBM Fields, SPE Applied Technology Workshop, Queensland, 30 March - 2 April, 2009

CSG Wellhead Facilities

Concept schematic – frothy water separator added

11

Production Management Best Practices for CBM Fields, SPE Applied Technology Workshop, Queensland, 30 March - 2 April, 2009

CSG Wellhead Facilities

Concept schematic – comingled water + gas through separator

12

Production Management Best Practices for CBM Fields, SPE Applied Technology Workshop, Queensland, 30 March - 2 April, 2009

CSG Wellhead Facilities

Concept schematic – comingled water + gas through separator

13

Production Management Best Practices for CBM Fields, SPE Applied Technology Workshop, Queensland, 30 March - 2 April, 2009

CSG Wellhead Facilities

New concept . . . . .Install nodal separation stations to eliminate wellhead separators

14

Production Management Best Practices for CBM Fields, SPE Applied Technology Workshop, Queensland, 30 March - 2 April, 2009

CSG Gathering Systems

VERTICAL SEPARATON TANK (MADE FROM LARGE DIAMETER HDPE GAS PIPE)

TO REDUCE HDPE PIPELAYING COST, WITH FAVOURABLE SLOPING GRADIENT CANHAVE SINGLE 2-PHASE GAS+WATER LINE FROM SELECTED WELLS

New concept . . . .Use of PCPump power for boosting gas pressure of weak wells

15

Production Management Best Practices for CBM Fields, SPE Applied Technology Workshop, Queensland, 30 March - 2 April, 2009

CSG Wellhead Facilities

HIGH PRESSURE WATER(FROM DOWNHOLE PC PUMP

WELLHEADEJECTOR

VERY LOW POSITIVE PRESSURE(OR VACUUM)

IN CASING

2-PHASE HDPE WATER+GAS LINETO NODAL SEPARATION STATION

(NEEDS TO HAVE SLIGHTDOWNWARD SLOPING

GRADIENT)

New concept . . . . .Eliminate inlet & oily water handling at central compression plant

16

Production Management Best Practices for CBM Fields, SPE Applied Technology Workshop, Queensland, 30 March - 2 April, 2009

CSG Gathering Systems & Central Gas Processing Facilities

NODAL (INFIELD)COMPRESSION STATION

HEATEXCHANGER

SKID

DX CHILLERPACKAGE*

“DRY” PIPELINE TOCENTRAL PLANT

* IF ELECTRICAL POWER NOT READILY AVAILABLE, USE NH3 ABSORPTION CHILLER POWERED BY COMPRESSOR ENGINE WASTE HEAT

Coal Seam Gas Wellhead Facilities

Some observations & ideas from Australian practice

Thank you for listening!

Any questions?

Geoffrey A . McKee +61 4186 777 51 SPE Member 3190919