Saudi Aramco use of formate brines, 2003-2009

• 7 deep gas fields

• 44 HPHT wells drilled

• 70,000 ft of reservoir drilled at high angle

• 90,000 bbl of brine recovered and re-used

• Good synergy with ESS, also OHMS fracturing

Summary from Aramco’s OTC paper 19801

Aramco still consume around 300 m3/month of K formate brine

SPE 132151 (2010) “Successful HPHT Application of Potassium Formate/Manganese Tetra-Oxide Fluid Helps Improve Drilling Characteristics and Imaging Log Quality”

SPE/IADC 147983 (2011) “Utilization of Non-damaging Drilling Fluid Composed of Potassium Formate Brine and Manganese Tetra Oxide to Drill Sandstone Formation in Tight Gas Reservoir

SPE 163301 (2012) “Paradigm Shift in Reducing Formation Damage: Application of Potassium Formate Water Based Mud in Deep HPHT Exploratory Well”

Potassium formate brine with Micromax®

Good results in Saudi Arabia and Kuwait (9 HPHT wells so far)

Pakistan - OMV use potassium formate brine for HPHT deep gas well drilling and completions

Extracts from OMV’s SPE papers and SPE presentations – note 1,700 psi overbalance, and 350oF

North Sea - Formate brines used as combined HPHT drill-in and completion fluids

33 development* wells drilled and completed in 7 HPHT offshore gas fields

•Huldra (6 ) •Tune (4) •Devenick (2) •Kvitebjoern (8 O/B and 5 MPD) •Valemon (1) •Kristin (2) – Drilled only •Vega (5)

* Except Valemon (appraisal well)

Mostly open hole stand-alone sand screen completions

Tune field – HP/HT gas condensate reservoir drilled and completed with K formate brine, 2002

4 wells : 350-900 m horizontal reservoir sections. Open hole screen completions. Suspended for 6-12 months in formate brine after completion

Tune wells - Initial Clean-up – Operator’s view (direct copy of slide) June 2003

• Wells left for 6-12 months before clean-up• Clean-up : 10 - 24 hours per well • Well performance

•Qgas 1.2 – 3.6 MSm3/d•PI 35 – 200 kSm3/d/bar•Well length sensitive

•No indication of formation damage•Match to ideal well flow simulations (Prosper) - no skin

• Indications of successful clean-up•Shut-in pressures  •Water samples during clean-up

•Formate and CaCO3 particles•Registered high-density liquid in separator•Tracer results

•A-12 T2H non detectable•A-13 H tracer indicating flow from lower reservoir first detected 5 sd after

initial clean-up <-> doubled well productivity compared to initial flow data•No processing problems Oseberg Field Center

SIWHP SIDHP SIWHP SIDHPbara bara bara bara

A-11 AH 169 - 388 -

A-12 T2H 175 487 414 510

A-13 H 395 514 412 512

A-14 H 192 492 406 509

Before After

3350

3400

3450

3500

3550

3600

0 100 200 300 400 500 600 700 800 900 1000

Well length [m MD]

Dep

th [

m T

VD

MS

L]

A-11AH

A-12HT2

A-13H

A-14H

A-11 AH plugged back

Tune – Production of recoverable gas and condensate reserves since 2003 (NPD data)

Good early production from the 4 wells - No skin (no damage) - 12.4 million m3 gas /day - 23,000 bbl/day condensate

Good sustained production - 90% of recoverable hydrocarbon reserves produced by end of Year 7

NPD current estimate of RR: - 18.3 billion m3 gas - 3.3 million bbl condensate

Rapid and efficient drainage of the reservoir

• 6 production wells

• 1-2 Darcy sandstone

• BHST: 147oC

• TVD : 3,900 m

• Hole angle : 45-55o

• Fluid density: SG1.89-1.96

• 230-343 m x 81/2” reservoir sections

• Open hole completions, 65/8” wire wrapped

screens

• Lower completion in formate drilling fluid and

upper completions in clear brine

Huldra field – HPHT gas condensate reservoir drilled and completed with formate brine, 2001

Huldra – Production of recoverable gas and condensate reserves since Nov 2001 (NPD data)

Plateau production from first 3 wells - 10 million m3 gas /day - 30,000 bbl/day condensate

Good sustained production - 78% of recoverable gas and 89% of condensate produced by end of Year 7 - Despite rapid pressure decline.....

NPD current estimate of RR: - 17.5 billion m3 gas - 5.1 million bbl condensate

Rapid and efficient drainage of the reservoir

• 13 wells to date – 8 O/B, 5 in MPD mode

• 100 mD sandstone

• BHST: 155oC

• TVD : 4,000 m

• Hole angle : 20-40o

• Fluid density: SG 2.02 for O/B

• 279-583 m x 81/2” reservoir sections

• 6 wells completed in open hole : 300-micron single wire-wrapped

screens.

• Remainder of wells cased and perforated

Kvitebjørn field – HPHT gas condensate reservoir drilled and completed with K/Cs formate brine, 2004-2013

A few of the highlights from Kvitebjoern

Kvitebjoern well

Completion time

(days)

A-4 17.5

A-5A-5 17.8

A-15 14.8

A-10A-10 15.9

A-6A-6 12.7 *

* Fastest HPHT well completion in the North Sea

“The target well PI was 51,000 Sm3/day/bar This target would have had a skin of 7”

“A skin of 0 would have given a PI of 100,000”

“THE WELL A-04 GAVE A PI OF 90,000 Sm3/day/bar (ANOTHER FANTASTIC PI)”

Operator comments after well testing (Q3 2004 )

The Well PI was almost double the target

Fast completions and high well productivity

Kvitebjørn– Production of recoverable gas and condensate reserves since Oct 2004 (NPD data)

Good production reported from first 7 wells in 2006 - 20 million m3 gas /day - 48,000 bbl/day condensate

Good sustained production (end Y8) - 37 billion m3 gas - 17 million m3 of condensate - Produced 70% of original est. RR by end of 8th year

NPD : Est. RR have been upgraded - 89 billion m3 gas (from 55) - 27 million m3 condensate (from 22)

Note : Shut down 15 months, Y3-5 - To slow reservoir pressure depletion - Repairs to export pipeline

Economic benefits of using formate brines

• SPE 130376 (2010): “A Review of the Impact of the Use of Formate Brines on the Economics of Deep Gas Field Development Projects”

• SPE 145562 (2011): “Life Without Barite: Ten Years of Drilling Deep HPHT

Gas Wells With Cesium Formate Brine”