Local experience regarding downhole surfactant injection ... · Local experience regarding downhole surfactant injection in south of France. 2 - J.Monsma (Total EP France), V.Peyrony

J.Monsma (Total EP France), V.Peyrony (Total SA)

Local experience regarding downhole surfactant injection in south of France

2 - J.Monsma (Total EP France), V.Peyrony (Total SA)

Meillon Saint Faust (MSF) field: challenging environment..Deep wells: ~4500 m (~13000 ft)Mainly 5'' completions, dual safety valves.Hot: 155 °C (310°F)Gas rates: ~ 50 KSm3/day (~ 1400*103scft/day)Water rates: WGR > 1500m3/106Sm3 (0.336 bbl/103Scft)Free condensates, 6 % H2S, 9% CO2Scales (CaCO3, BaSO4)Nearby separators and compressors (defoaming required!)HSE & Safety requirements…


PROJECT HISTORY“Dewatering” main topic of "Water Management on the Meillon field“

‘’Cap. String’’ project start-up date: December 2005

Project set-up in 3 phases:

Phase 1: Through samplings and analysis: search for the best adapted chemical(s), followed by a first set of tests on several wells. Search for the best adapted surfactant(s).

Phase 2: Enhanced well-testing through batch-injections (appropriate treatments volumes).Searching for the most economical injection-mode of surfactants / selected well (Batch versus Capillary String). Sizing of the future pilot of continuous surfactant injection.

Phase 3: Design & execution of the continuous surfactant injection pilot:

Status Sept. 2007: One cap-string installed (LLT1), one in progress.


PHASE 1 (Dec 2005 - Mar 2006)

Selection of specialized company to assist the project. Services, chemical selection, injection optimization

Sampling and analysis of liquid phases on 8 (MSF) wells BAY 1, LLT 6, MZS 4, PTS 3, PTS 5bis, RSE 1, RSE 3, SFT 16.

Laboratory selection of foamer & defoamer agent compatible with the field conditions:

Foaming agent: shall also be inhibitor carrier – ''green'' product requiredDefoamer: non-solvant based: no BTX

Solid surfactant tests (foam sticks) (very promising on PTS 5bis)Conclusion: sticks not industrially feasible….

Liquid surfactant tests on BAY 1 and MZS 4 (both had good reaction)

Conclusion: obvious interest to continue….obvious interest to continue….


Objectives:To determine the most suitable surfactant injection mode on MSF wells.

Confirm suitability of selected chemicals.

Sizing of the future continuous surfactant injection pilot on 2 wells.

Main Works:

Reference testing of wells (reference shut-ins and start-ups, dry runs, wireline)

Double batch-treatments on 7 wells (PTS 5bis, LLT 4, BAY 1, SFT 7, MZS 4, SFT 16, LLT 1).

Interpretation of batch-tests.

PHASE 2 (Field tests: Sept - Oct 2006)


LLT1 surfactants tests phase 2

-10

0

10

20

30

40

50

60

70

80

27-s

ept-0

6 / 0

0

27-s

ept-0

6 / 0

6

27-s

ept-0

6 / 1

2

27-s

ept-0

6 / 1

8

28-s

ept-0

6 / 0

0

28-s

ept-0

6 / 0

6

28-s

ept-0

6 / 1

2

28-s

ept-0

6 / 1

8

29-s

ept-0

6 / 0

0

29-s

ept-0

6 / 0

6

29-s

ept-0

6 / 1

2

29-s

ept-0

6 / 1

8

30-s

ept-0

6 / 0

0

30-s

ept-0

6 / 0

6

30-s

ept-0

6 / 1

2

30-s

ept-0

6 / 1

8

01-o

ct-0

6 / 0

0

01-o

ct-0

6 / 0

6

01-o

ct-0

6 / 1

2

01-o

ct-0

6 / 1

8

02-o

ct-0

6 / 0

0

02-o

ct-0

6 / 0

6

02-o

ct-0

6 / 1

2

02-o

ct-0

6 / 1

8

03-o

ct-0

6 / 0

0

03-o

ct-0

6 / 0

6

03-o

ct-0

6 / 1

2

03-o

ct-0

6 / 1

8

04-o

ct-0

6 / 0

0

04-o

ct-0

6 / 0

6

04-o

ct-0

6 / 1

2

04-o

ct-0

6 / 1

8

05-o

ct-0

6 / 0

0

time

WH

P (B

arg)

- Q

GA

S (K

Sm3/

d)

35

40

45

50

55

60

65

70

75

80

85

90

95

100

105

110

115

120

125

Dow

nhol

e gu

age

pres

sure

(Bar

a)

LLT1 - WHP LLT1 GasRate downhole guage pressure

Phase 2: LLT1: reference test & downhole pressure reaction…

Reference start-up (no surfactant)

Well unloadingFirst surfactant batch

Roughly 15 KSm3/d gain in gas flow

Roughly 10 bars reduction in BHFP


PHASE 2: results…

(m3)(KSm3)

Shut-down during flow-back

0

4 m30

2 : 150 L

2 : 150 L

2 : 350 L

2 : 125 L

++ +Eased start upT° increase

1 : 350 L38INTERMITTENT

SFT 7

+ + ++ 100 m325 KSm31 : 100 L

15LLT 1G2

+ + ++40 m311 KSm31 : 625 L70SFT 16

+ To be

evaluated-T° increase

01 : 75 L25MZS 4

++ + +- 6 m338 KSm31 : 175 L68BAY 1

- -- -6 m301 : 250 L

75PTS 5bis

- -- -001: 350 L190LLT 4

CAPILLARYBATCH

Gain of waterafter 30 hrs

Gain of gas after 30 hrs

BatchQ before treatment(KSm3/day)

WELL


BAY 1… Batch performanceBatch 2Batch 1

(MultiChem)

Gaz doux

fermetures SC Gaz doux

Batch 4 Batch 6 Batch 7 Batch 8Batch 5Batch 3

sans assistence

mini-batch de test (MultiChem)

Gaz doux

Gaz doux

Negative attempts to start well by rocking

Self-killing problems…

First surfactant batch

Negative attempts to start well by rocking


PHASE 3: MSF CAPILLARY STRING PRINCIPLEWELL equipment:

Use of the existing lower SCSSV-nipple for landing string hanger. Cap-string hanger with integrated check-valve.String-end run on top of first production zone (LLT1 4400mD: to top of the slots in liner) A pressure rated bottom check-valve to maintain full column-weight of the surfactant within the capillary.

SURFACE equipment:Injection-system of surfactant in the well (through the control line of lower down hole safety valve)Injection-system of defoamer in the well's production line.

Cap String Running principle:Hydraulic unit (mini CTU) to run ¼’’ cap-string in hole. BOP stack with slip rams to hang-of string during swab from injector-head to HD wireline.HD slick-line unit to end the descent and set the suspension.


PHASE 3: LLT1 CAPILLARY STRING OPERATIONMain actors:

BJ Services – Dyna Coil , Emmen – Netherlands.string design, coil delivery, running equipments, program and job execution

The Expro Group , Emmen & Aberdeen. wireline services: string and hanger landing


PHASE 3: LLT1 CAPILLARY STRING OPERATION


PHASE 3: LLT1 CAPILLARY STRING OPERATION

Reel with 9175 m (28000 ft) ¼’’ string Inconel 625

Pressure rated bottom check valve (400 bar - 5800 PSI)

HD-slickline wire (0.160'') to run hanger to nipple.

Injection system with 50µ HP-filters; anti-siphon (!), dP, P and PSH transmitting.


PHASE 3: LLT1 CAPILLARY STRING OPERATION (27- 30 Aug2007).

Smooth ….Un-reeling of coil caused some challenges: loose windings on reel as from manufacturer.One real with single length for 2 wells: to be avoided.HD slickline unit 0.160’’ wire): not a conventional unit, especially at -63 m depth.

Successful descent of coil to planned depth of 4400 mDTriple depth indication during descent: 1:weight – 2:check valve hold-open pressure vs depth – 3:depth counter.Proven hanger-seal tightness trough injection pressure increase while landing (rated check valve).

BJ/Dyna hanger-design and running procedures = good quality.Inconel 625 capillary and Uranus45N hanger material (H2S service).All pull and pressure tests ok on first attempts.

Good job preparation, service quality, HSE and team spirit onsite.

Second well (MSZ4) soon………………


LLT1 start-up with Cap-string injection (03-Sep-2007).Surfactant injection on LLT1 started 03-Sep-2007….:

Surfactant injection pressure behavior not yet fully understood: obvious coil ballooning/stretching/Torricelli effects vs pressure rated check valve?

Clear evidence of frictional P-difference when pumping water or surfactant !!! (density understood but coil friction and friction though check valve: not)

Clear evidence of big difference between check-valve opening pressure and hold-open pressure !!! (> 120 bars in our case: temperature dependent?)

Unexpected storage-tank siphoning, despite rated bottom check-valve & regardless volumetric pump: anti-siphon valve installed ASAP.

………….

Assistance from MULTICHEM, Oklahoma USA.

(Basic cap-string injection rules: never stop injection, inject one string-volume/day, in case prolonged stop rinse string with de-mineralized water, ….)


LLT1 Cap-string injection (started 03-7-2007).

0

10

20

30

40

50

60

70

80

90

100

03-s

ept-0

7

04-s

ept-0

7

05-s

ept-0

7

06-s

ept-0

7

07-s

ept-0

7

08-s

ept-0

7

09-s

ept-0

7

10-s

ept-0

7

11-s

ept-0

7

12-s

ept-0

7

13-s

ept-0

7

14-s

ept-0

7

15-s

ept-0

7

temps

Ptêt

e, Q

gaz,

Tco

mpt

age

0

20

40

60

80

100

120

140

160

Pinj

ectio

n, Q

inje

ctio

n su

rfac

tant

< LLT1 FWHP (bar) < LLT1 Gas (KSm3/d) < LLT1 T-flowline (degC) > P.injection Surfactant (bar) > Surfactant Injection rate (ltr/d)


0

100

200

300

400

500

600

700

03-s

ept-0

7

04-s

ept-0

7

05-s

ept-0

7

06-s

ept-0

7

07-s

ept-0

7

08-s

ept-0

7

09-s

ept-0

7

10-s

ept-0

7

11-s

ept-0

7

12-s

ept-0

7

13-s

ept-0

7

14-s

ept-0

7

15-s

ept-0

7

time

Acc

umul

ativ

m3

liqui

d -K

Sm3

gas

0

1000

2000

3000

4000

5000

6000

7000

WG

R m

3/10

^6Sm

3

Accum. Gas LLT1 Accum. liquid LLT1 > Surfactant Injection rate (ltr/d)

WGR LLT1: average/2hrs

LLT1 Cap-string injection (observation:).

good deliquification !!


CONCLUSIONS CAP-STRING Project on MSF (so far….)

Surfactants technology is applicable on Meillon Saint-Faust field:High temperature / Deep / H2S / Condensates / ….Lifting of ‘’normally non-érutpitve WGR ‘s !!LLT1 reaction shows deliquification potential !!

Key-factor is selection to get a good fit between wells and chemicals.Efficiency of foamer & defoamer/breaker, correct dosage (foam locking), …. Products are compatible HSE (green): no process impact (yet).

Not so easy application on selected wells.Work over avoided (use of second SCSSV nipple) but stabilization of injection through check valve difficult to achieve so far..Successful descent on LLT1 !!

Importance of (production) team implication.Follow-up of the well's production and decline (optimization batch or dosage) Analysis and time of reaction.

Economical.BAY1 batch treatments: 33 K€ expenditures vs 3740 K€ gas-revenue in 8 months.LLT1 cap string: CAPEX: estimated 7 months pay-out (at 35 KSm3/day > dependent on water cost).


Quick Messages…. (TEPF's "Surfactants learning curve")…..

Well reaction appears unpredictable ►do not assume: field test your well !

Know the bottleneck ►be sure it's the loading of fluid gradient in well bore.

Do not underestimate surface constraints ►process impact, safety logic, manpower.

Sometimes, water appears to be condensate ►sampling & testing procedures

Persevere in field testing: learning curve…..

Documents

Local experience regarding downhole surfactant injection ... · Local experience regarding downhole surfactant injection in south of France. 2 - J.Monsma (Total EP France), V.Peyrony