< Resources

Field List

Our products and services can enable optimum returns in challenging high-pressure, high-temperature (HPHT) operations for many of the world's largest international exploration and production (E&P) companies.

BP: Raven, Egypt, Completion

  • Year: 2018
  • Application: Gravel Pack
  • Density: 1.79 g/cm3 / 14.94 lb/gal
  • Temperature: 135°C / 275°F
  • Description: Cesium/potassium formate has been used as carrier fluid for gravel pack completions and for well clean-up pills after drill-in with OBM, on multiple wells. 

Oil India: KG Basin, India, Kill Fluid

  • Year: 2018
  • Application: Well kill (standby fluid)
  • Density: 1.94 g/cm3 / 16.19 lb/gal 
  • Temperature: 216°C / 420°F
  • Description: Cesium/potassium formate acted as standby kill fluid during well test operations.

ONGC: Bantmilli South-3, India, Well Testing Fluid and Completion

  • Year: 2017
  • Application: Well test, perforation fluid
  • Density: 2.06 g/cm3 / 17.2 lb/gal
  • Temperature: 192°C / 378°F
  • Description: Clear cesium/potassium formate brine was used on land for a perforating operation and four successful HPHT well tests in India.

Chevron: Alder, UK North Sea, Completion

  • Year: 2016
  • Application: Upper completion
  • Density: 2.16 g/cm3 / 18.03 lb/gal
  • Temperature: 151°C / 304°F
  • Description: High-density cesium formate was used as over-balanaced upper-completion fluid in the HPHT Alder field.

Wintershall: Ravn, Denmark, Well Kill

  • Year: 2016
  • Application: Well Kill
  • Density: 2.20 g/cm3 / 18.4 lb/gal
  • Temperature: 140°C / 284°F
  • Description: Cesium formate successfully burst the coiled tubing and created an ice plug seal during a unique intervention and well kill operation.

Total E&P Norge: Martin Linge, Norway North Sea, Drilling and Completion

  • Year: 2015 - 2017
  • Application: Drill-in, screen running, upper completion
  • Density: Up to 2.13 g/cm3 / Up to 17.8 lb/gal
  • Temperature: 135°C / 275°F
  • Description: 2.01–2.13 g/cm/ 16.8–17.8 lb/gal cesium/potassium formate drill-in fluid was used to successfully drill the reservoir section of one well, with the same fluid (screened over API270 mesh) used to run 250µm production screens. Clear cesium/potassium formate brine also provided trouble-free upper completion installation for this well and three others in the field.  
  • References: SPE 189550

ConocoPhillips: Ekofisk, Norway North Sea, Completion

  • Year: 2014 - present
  • Application: TP&A, Upper Completion
  • Density: 1.65 g/cm3 / 13.77 lb/gal
  • Temperature: 136°C / 277°F
  • Description: Cesium/potassium formate was used for a TP&A operation and upper completion. 

Statoil: Gudrun, Norway North Sea, Completion

  • Year: 2013 - 2014
  • Application: Upper completion
  • Density: Up to 2.15 g/cm3 / Up to 17.94 lb/gal
  • Temperature: 147°C / 297°F
  • Description: 1.70–2.15 g/cm3 / 14.2–17.94 lb/gal cesium/potassium formate brine was used for two upper completions under HPHT conditions.

Maersk: Boje, Denmark North Sea, Kill Fluid

  • Year: 2013
  • Application: Well kill
  • Density: 2.16 g/cm3 / 18.0 lb/gal
  • Temperature: 0 °C / 0 °F
  • Description: Cesium formate brine was used to kill sustained casing pressure behind the production casing by bullheading the fluid down the casing annulus.

Statoil: Vigdis, Norway North Sea, Completion

  • Year: 2007 - 2014
  • Application: Upper completion, perforation
  • Density: 1.98 g/cm3 / 16.5 lb/gal
  • Temperature: 108°C / 226°F
  • Description: Cesium/potassium formate used as perforation fluid (kill pill) and completion brine for upper completion.

ONGC: Yanam South, India, Completion, Well Test Fluid

  • Year: 2013
  • Application: Completion, injection tests
  • Density: 1.90 g/cm3 / 15.8 lb/gal
  • Temperature: Up to 198°C / 388°F
  • Description:Two wells were completed and injectivity tests conducted using cesium/potassium formate brine.

Brunei Shell Petroleum: Champion Deep, Brunei, Completion

  • Year: 2016 - 2017
  • Application: Upper completion, clean-up pills
  • Density: 1.90 g/cm3 / 15.86 lb/gal
  • Temperature: 102 °C / 216 °F
  • Description: High-density cesium/potassium formate brine was used for upper completions on two wells offshore Brunei. Cesium formate also formed the base for high-density clean-up pills.

Brunei Shell Petroleum: Champion West, Brunei, Completion

  • Year: 2008 - 2017
  • Application: Upper completion, clean-up pills
  • Density: 2.09 g/cm3 / 17.4 lb/gal
  • Temperature: 116 °C / 241 °F
  • Description: Cesium/potassium formate brine was chosen as upper completion fluid for seven wells in the Champion West field, offshore Brunei. Cesium formate also formed the base for high-density clean-up pills.
  • References: OTC 26474

Lundin: Brynhild, Norway North Sea, Completion

  • Year: 2013 - 2015
  • Application: Intermediate and upper completions, TP&A
  • Density: 2.15 g/cm3 / 17.94 lb/gal
  • Temperature: 150°C / 302°F
  • Description: Cesium/potassium formate was used for intermediate- and upper-section completions on four wells. Formate brine also formed the base fluid for a perforation kill pill and was used for TP&A on two wells.

ONGC: Mumbai High, India, Completion and Test Fluid

  • Year: 2012
  • Application: Perforation fluid, DST, upper completion, gravel pack
  • Density: 1.82 g/cm3 / 15.2 lb/gal
  • Temperature: 135°C / 275°F
  • Description: One well was perforated overbalanced in 1.82 g/cm/ 15.2 lb/gal cesium/potassium formate brine. A DST was performed. The upper completion was installed in cesium/potassium formate brine after gravel packing.

Petronas: Kanowit, Malaysia, Drilling, Completion and Kill Fluid

  • Year: 2012
  • Application: MPD drill-in, perforated liner, upper completion, well kill (standby fluid)
  • Density: 1.83 g/cm3 / 15.3 lb/gal
  • Temperature: 130°C / 266°F
  • Description: Two wells were drilled in MPD mode into a fractured carbonate reservoir using sodium/potassium formate drilling fluid. A 1.83 g/cm3 / 15.3 lb/gal cesium/potassium formate drilling fluid was used for tripping and stand-by kill fluid. Wells were completed in openhole using 7" pre-drilled liners in the cesium formate tripping fluid. Upper completions were installed in cesium formate brine.
  • References: Field Case Study, Kanowit; SPE 164573; SPE 165761; IPTC 16697

Dong Energy: Oselvar, Norway North Sea, Completion

  • Year: 2011
  • Application: LSOBM
  • Density: 2.20 g/cm3 / 18.36 lb/gal
  • Temperature: 0°C / 0°F
  • Description: Cesium formate brine was used as the internal phase in LSOBM (low-solids oil-based mud). 

BP: Snadd North, Norway North Sea, Completion

  • Year: 2011
  • Application: Gravel pack
  • Density: 1.52 g/cm3 / 12.7 lb/gal
  • Temperature: 91°C / 196°F
  • Description: BP used 1.52 g/cm3/12.7 lb/gal cesium formate brine to gravelpack a well in openhole, previously drilled with oil-based mud. Diluted cesium formate brine was chosen because of its lower reactivity with kaolinite shale compared to potassium formate brine. The diluted cesium formate brine was also left in the well as packer fluid.

Delta Petroleum: North Vega, USA, Completion

  • Year: 2011
  • Application: Completion
  • Density: 1.81 g/cm3 / 15.1 lb/gal
  • Temperature: 193°C / 380°F
  • Description: A 1.81 g/cm3 / 15.1 lb/gal cesium/potassium formate brine was used as completion fluid in the Piceance Basin shale formation. 

ConocoPhillips: Edith Gray, USA, Kill Fluid

  • Year: 2011
  • Application: Well kill
  • Density: 2.17 g/cm3 / 18.1 lb/gal
  • Temperature: 0°C / 0°F
  • Description: A 2.17 g/cm3 / 18.1 lb/gal cesium formate brine was used as well kill fluid in Eagle Ford shale.

Dong Energy: Trym, Norway North Sea, Completion

  • Year: 2010 - 2011
  • Application: Completion, LSOBM
  • Density: 2.13 g/cm3 / 17.8 lb/gal
  • Temperature: 0°C / 0°F
  • Description: Dong used cesium/potassium formate brine as the internal phase in LSOBM (low-solids oil-based mud) to complete two gas condensate production wells in the Trym field.

Oil Search (PNG): Moran, Papua New Guinea, Completion

  • Year: 2010
  • Application: Perforation
  • Density: 1.66 g/cm3 / 13.9 lb/gal
  • Temperature: 38°C / 100°F
  • Description: First deployment of cesium formate in Papua New Guinea. Multi-zonal perforation was performed in cesium/potassium formate fluid using two brine densities. 

Statoil: Alve, Norway North Sea, Completion

  • Year: 2010
  • Application: LSOBM Completion
  • Density: 2.00 g/cm3 / 16.7 lb/gal
  • Temperature: 141°C / 286°F
  • Description: Statoil completed one well in the Alve field with LSOBM (low-solids oil-based mud) using cesium formate brine in the internal phase.

Total E&P: Hild, Norway North Sea, Completion

  • Year: 2010
  • Application: Upper completion, TP&A
  • Density: 2.04 g/cm3 / 17.0 lb/gal
  • Temperature: 139°C / 282°F
  • Description: Total completed one well in the Hild field with 2.04 g/cm3 / 16.7 lb/gal cesium/potassium formate brine. Formate brine was also used in a second well for TP&A.

ConocoPhillips: Malek, USA, Kill Fluid

  • Year: 2010
  • Application: Well kill
  • Density: 1.94 g/cm3 / 16.4 lb/gal
  • Temperature: 0°C / 0°F
  • Description: Conoco used high-density cesium/potassium formate brine for a well kill in Eagleford shale.

Statoil: Morvin, Norway North Sea, Completion

  • Year: 2010 - 2011
  • Application: Liner running, upper completion, RS-OBCF
  • Density: 1.98 g/cm3 / 16.5 lb/gal
  • Temperature: 162°C / 324°F
  • Description: RS-OBCF (reduced-solids oil-based completion fluid) with cesium formate in the internal phase was used in six 8.5" horizontal reservoir sections when installing 5.5" predrilled liners with swell packers, previously qualified for cesium formate brine and oil-based mud environments.The reservoir sections had earlier been drilled with oil-based mud. Wells were later displaced from RS-OBCF to cesium formate ready for installation of the upper completion.
  • References: OTC 21476

Statoil: Vega, Norway North Sea, Drilling and Completion

  • Year: 2009 - 2011
  • Application: Drill-in, openhole sand screen, upper completion, perforated liner, suspension, TP&A
  • Density: Up to 1.83 g/cm3 / 15.3 lb/gal
  • Temperature: 133°C / 271°F
  • Description: Statoil used cesium/potassium formate (1.63–1.83 g/cm3 / 13.6–15.3 lb/gal) to drill and complete several wells in the Vega reservoir. Five wells were drilled and completed with openhole sand screens run in cesium/potassium formate. Three wells were tested, plugged and abandoned, and three reservoirs were perforated in formate brine after drilling with oil-based mud. One well was suspended with cesium/potassium formate brine. Upper completions were also installed in cesium/potassium formate brines. 

Total E&P: Victoria, Norway North Sea, Well Test Fluid

  • Year: 2009
  • Application: DST
  • Density: 1.76 g/cm3 / 14.7 lb/gal
  • Temperature: 200°C / 405°F
  • Description: Total used high-density cesium/potassium formate brine to perform a DST in an exploration well in the Victoria field.

Total E&P: Kessog, UK North Sea, Completion and Test Fluid

  • Year: 2009
  • Application: Perforated liner, well test, long-term suspension 
  • Density: 2.14 g/cm3 / 17.9 lb/gal
  • Temperature: 170°C / 305°F
  • Description: Total perforated one well in overbalance using a cesium formate fluid-loss pill in the Kessog reservoir. A five-day well test was conducted after perforating. The well was then suspended with cesium formate brine to enable a 90-day pressure build-up test. 
  • References: SPE 165151

ExxonMobil: Jerneh, Malaysia, Completion

  • Year: 2008
  • Application: Completion
  • Density: 1.65 g/cm3 / 13.8 lb/gal
  • Temperature: 0°C / 0°F
  • Description: ExxonMobil used 1.65 g/cm3 / 13.8 lb/gal cesium/potassium formate brine to complete two wells in the Jerneh field, Malaysia.

AgipKCO: Kashagen, Kazakhstan, Completion

  • Year: 2008 - 2010
  • Application: Completion, workover
  • Density: 2.03 g/cm3 / 16.9 lb/gal
  • Temperature: 100°C / 212°F
  • Description: Agip KCO used high-density cesium formate brine to complete 12 wells in the Kashhagan field in Kazakhstan. Two wells were later worked over with cesium formate brine.

ConocoPhillips: Baker Family Trust, USA, Compeltion and kill fluid

  • Year: 2008
  • Application: Well kill, openhole completion
  • Density: 1.98 g/cm3 / 16.5 lb/gal
  • Temperature: 0°C / 0°F
  • Description: A well was killed and completed in openhole with high-density cesium/potassium formate brine.

Total E&P: Jura, UK North Sea, Completion

  • Year: 2008
  • Application: Perforated liner, perforation
  • Density: 2.09 g/cm3 / 17.4 lb/gal
  • Temperature: 123°C / 253°F
  • Description: Total used high-density cesium/potassium formate brine to perforate two wells drilled with OBM in the Jura field. The wells were perforated overbalanced in fluid-loss pills with xanthan, fluid-loss polymers and added calcium carbonate. The Jura reservoir has pressure of 70.2 MPa/10,182 psi.
  • References: SPE 165151

NAM: Gasselternijveen, Netherlands, Completion

  • Year: 2008
  • Application: Workover, perforated liner
  • Density: 1.90 g/cm3 / 15.9 lb/gal
  • Temperature: 129°C / 264°F
  • Description: NAM (Shell) used cesium/potassium formate brine to work over a well in the Gasselternijveen field offshore Netherlands.

ExxonMobil: Tapis, Malaysia, Completion

  • Year: 2007
  • Application: Perforation fluid
  • Density: 1.71 g/cm3 / 14.3 lb/gal
  • Temperature: 160°C / 320°F
  • Description: ExxonMobil's application of high-density cesium/potassium formate brine in the Tapis field was the first use of cesium formate in Asia.

TXM: Mako, Hungary, Completion and Kill Fluid

  • Year: 2007 - 2008
  • Application: Workover, frac pack, well kill, suspension
  • Density: 2.15 g/cm3 / 17.9 lb/gal
  • Temperature: 235°C / 455°F
  • Description: High-density cesium formate brine was used during a well appraisal in an extreme HPHT well, setting a temperature record for use of cesium formate at 235°C / 455°F. The well was later killed twice and suspended three times with cesium formate. The longest suspension lasted around six months.
  • References: Field Case Study, TXM - Mako 6

Petrobras: El Campamento, Argentina, Drilling, Completion and Kill Fluid

  • Year: 2006
  • Application: Drill-in, completion, well kill
  • Density: 1.95 g/cm3 / 16.3 lb/gal
  • Temperature: 138°C / 280°F
  • Description: This was the first cesium formate job in South America. An 8.5" reservoir section was drilled with potassium formate fluid supplied by Halliburton. The fluid was gradually weighted up with cesium formate brine until it reached density of around 1.95 g/cm3 / 16.3 lb/gal. Logging of the well revealed an almost gauge hole with negligible washouts.

Norsk Hydro: Oseberg Vestflanke, Norway North Sea, Completion

  • Year: 2006
  • Application: LSOBM
  • Density: 1.64 g/cm3 / 13.7 lb/gal
  • Temperature: 0°C / 0°F
  • Description: Norsk Hydro used LSOBM (low-solids oil-based mud) to complete a well in the Oseberg Vestflanke reservoir.

Total E&P: Glenelg, UK North Sea, Completion

  • Year: 2005
  • Application: Perforated liner
  • Density: 2.22 g/cm3 / 18.5 lb/gal
  • Temperature: 195°C / 383°F
  • Description: Total performed overbalanced perforation of an extreme HPHT well (5,600m TVD) with 2.22 g/cm3 / 18.5 lb/gal cesium formate brine in the Glenelg gas field. The single Glenelg well with reservoir pressure of 115 MPa/16,700 psi was drilled with oil-based mud and perforated in high-density cesium formate brine without blocking pills. Only 2 m3 of cesium formate brine were lost on perforating, with a further 15.7 m3 of seepage losses later.
  • References: SPE 165151; SPE 113835

MOL: Vetyêm, Hungary, Completion

  • Year: 2005
  • Application: Frac pack completion
  • Density: 1.90 g/cm3 / 15.9 lb/gal
  • Temperature: 160°C / 320°F
  • Description: MOL performed a frac pack in an onshore HPHT well with high-density cesium/potassium formate brine.

ConocoPhillips: Judy, UK North Sea, Completion

  • Year: 2005
  • Application: Perforated liner, upper completion
  • Density: 1.98 g/cm3 / 16.5 lb/gal
  • Temperature: 160°C / 320°F
  • Description: ConocoPhillips used 1.98 g/cm3 / 16.5 lb/gal cesium/potassium formate brine to perforate a well in the Judy reservoir. The well was perforated overbalanced and the upper completion installed in the clear formate brine.
  • References: SPE 165151SPE 103244

BP: Rhum, UK North Sea, Completion

  • Year: 2004 - 2006
  • Application: Perforation fluid, long-term suspension
  • Density: 2.19 g/cm3 / 18.3 lb/gal
  • Temperature: 149°C / 300°F
  • Description: BP used high-density cesium formate fluid-loss pills to perforate two wells using dynamic underbalance in the Rhum HPHT gas/condensate reservoir (149°C / 300°F). The third well was perforated at balance. All wells cleaned up quickly. One well was suspended in cesium formate brine for 250 days.
  • References: SPE 165151; OTC 19242; Field Case Study, Rhum

Dong Energy: South Arne, Denmark, Completion

  • Year: 2004
  • Application: Perforated liner, perforation
  • Density: 1.82 g/cm3 / 15.2 lb/gal
  • Temperature: 115°C / 239°F
  • Description: Dong Energy perforated one well in the South Arne field overbalanced in a 1.82 g/cm3 / 15.2 lb/gal cesium/potassium formate fluid-loss pill. This was the first cesium formate application in a carbonate reservoir.

Walter Oil & Gas: Mobile Area, USA, Completion

  • Year: 2004 - 2005
  • Application: Openhole slotted liner, completion, workover
  • Density: 2.06 g/cm3 / 17.2 lb/gal
  • Temperature: 216°C / 420°F
  • Description: Walter Oil & Gas worked over a deep extreme HPHT well (216°C/420°F, 6,699 m) with barefoot completion using 1.90 g/cm3 / 15.9 lb/gal cesium/potassium formate brine. A 1.44 g/cm3 / 12 lb/gal sodium/potassium formate brine packer fluid was used for 12 months.

Saudi Aramco: Tinat, Saudi Arabia, Drilling and Completion

  • Year: 2004
  • Application: Drill-in, drilling, openhole sand screen
  • Density: 1.62 g/cm3 / 13.5 lb/gal
  • Temperature: 135°C / 275°F
  • Description: Potassium/sodium formate was used as a reservoir drilling fluid and expandable sand screen running fluid on two wells.

Statoil: Valemon, Norway North Sea, Drilling and Completion

  • Year: 2006-2013
  • Application: Extended-reach drilling, perforated liner
  • Density: 2.09 g/cm3 / 17.4 lb/gal
  • Temperature: 150°C / 302°F
  • Description: Statoil drilled an extended-reach exploration well into the Valemon gas/condensate reservoir from the Kvitebjørn platform. The 705 m (2,313 ft) reservoir section of this 7,380 m (24,213 ft) long well with an inclination of 69° was successfully drilled with 2.09 g/cm3 / 17.4 lb/gal cesium/potassium formate drilling fluid.
  • References: SPE 105733; SPE 174217

Statoil: Kvitebjørn, Norway North Sea, Drilling and Completion

  • Year: 2004 - present
  • Application: MPD drilling, drill-in, perforation fluid, openhole sand screen, upper completion
  • Density: 2.09 g/cm3 / 17.4 lb/gal
  • Temperature: Up to 155°C / Up to 311°F
  • Description: From 2004 to 2006, nine HPHT (up to 155°C/311°F, 81 MPa, 11,700 psi) reservoir sections were drilled and seven completed with 2.09 g/cm3 / 17.4 lb/gal cesium/potassium formate brine. The wells had inclinations varying between 20° and 45°. Seven of the wells were completed with openhole stand-alone sand screens and two with cemented liners. Since 2007, five further reservoir sections have been drilled and completed using lighter cesium/potassium formate drilling fluid. These wells were drilled in MPD mode. The designer fluid from MI Swaco was based on low ECD cesium/potassium formate brine. Stand-alone sandscreens were installed in kill-weight cesium/potassium formate drilling fluid.
  • References: SPE 105733; Field Case Study, Kvitebjørn 2004 - 2007Field Case Study, Kvitebjørn 2007 - present

Statoil: Kristin, Norway North Sea, Drilling and Completion

  • Year: 2003 - 2008
  • Application: Drill-in, coring, openhole completion, upper completion, workover
  • Density: 2.09 g/cm3 / 17.4 lb/gal
  • Temperature: 175°C / 347°F
  • Description: Two HPHT reservoir sections were drilled, cored and logged in 2.09 g/cm3 / 17.4 lb/gal cesium/potassium formate drilling fluid in the Kristin field, with their upper completions also installed in cesium/potassium formate brine. In addition, ten upper completions were installed in cesium/potassium formate brine in wells drilled with OBM. Two workovers and one recompletion with cesium/potassium formate brine followed later.
  • References: SPE 103336

Marathon: Braemar, UK North Sea, Completion

  • Year: 2003
  • Application: Perforation fluid, completion
  • Density: 1.86 g/cm3 / 15.5 lb/gal
  • Temperature: 136°C / 276°F
  • Description: Marathon used 1.86 g cm3 / 15.5 lb/gal cesium/potassium formate brine to re-perforate and complete the reservoir section in the only well in the Braemar field offshore UK. The well had been abandoned for eight years after it was tested and killed with OBM. The re-perforation was conducted at 5.69 MPa/825 psi overbalance without kill pills or any other blocking technologies. However, only 2.3 m3 of brine was lost to the formation from the 302 m3 brine deployed in the operation.
  • References: SPE 165151

Statoil: Gullfaks and Gullfaks Satellites (Rimfaks, Sør, etc.), Norway North Sea, Compeltion and Kill Fluid

  • Year: 2003 - present
  • Application: Completion, perforation fluid, workover, LSOBM, TP&A, gravel pack, kill pill, slug
  • Density: 1.96 g/cm3 / 16.36 lb/gal
  • Temperature: 128°C / 262°F
  • Description: Over 18 upper completions have been successfully completed using cesium/potassium formate. In 2013, Statoil performed its first gravel-pack operation with cesium formate as carrier fluid on a Gullfaks Satellite well. The fluid was a 1.63 g/cm3 / 13.6 lb/gal cesium/potassium blend. Low-solids OBM with cesium formate as the internal phase was used as screen-running fluid in over ten wells. Cesium formate has also been used as spike fluid, when drilling in with potassium formate drilling fluid. In 2011, a well with collapsed tubing was worked over; heavy cesium/potassium formate mud was blended with the packer fluid before the old tubing was pulled out. Cesium formate brine also been utilized for TP&A, perforation/kill pills and for pipe slugs on many occasions.

Norsk Hydro/Statoil: Njord, Norway North Sea, Completion and Kill Fluid

  • Year: 2003 - 2012
  • Application: LSOBM, kill pill
  • Density: 1.72 g/cm3 / 14.4 lb/gal
  • Temperature: 121°C / 250°F
  • Description: Statoil utlilized cesium formate as the internal phase in LSOBM (low-solids oil-based mud) in the Njord field and cesium/potassium formate brine as slug and kill pills.

Statoil: Statfjord, Norway North Sea, Completion

  • Year: 2002 - 2003
  • Application: Gravel pack, LSOBM
  • Density: 1.65 g/cm3 / 13.8 lb/gal
  • Temperature: 85°C / 185°F
  • Description: Statoil drilled three reservoir sections with potassium formate drilling fluid in the Statfjord reservoir. The wells were gravel packed with potassium formate carrier fluid. During this work, 1.65 g/cm3 / 13.8 lb/gal cesium formate was used as spike and stand-by fluid. Cesium formate brines have also been used as the internal phase in low-solids OBM screen-running fluids for three Statfjord Satellite wells.

Norsk Hydro/Statoil: Snorre , Norway North Sea, Completion

  • Year: 2002 - present
  • Application: Openhole sand screen, perforation, RSOBCF
  • Density: 1.76 g/cm3 / 14.7 lb/gal
  • Temperature: 85°C / 185°F
  • Description: Norsk Hydro used a potassium formate fluid-loss pill to complete several oil reservoir sections in the Snorre field. The fluid was used for screen-running and/or as a perforation pill. 1.65 g/cm3 / 13.8 lb/gal cesium/potassium formate brine has also been used to spike up the potassium formate fluid-loss system as required. On the latest wells, RSOBCF (reduced-solids oil-based completion fluid) with cesium formate in the internal phase was used for the same type of applications.

Norsk Hydro: Tune, Norway North Sea, Completion and Suspension Fluid

  • Year: 2002
  • Application: Openhole sand screen, long-term suspension
  • Density: 1.65 g/cm3 / 13.8 lb/gal
  • Temperature: 131°C / 267°F
  • Description: Norsk Hydro completed four gas/condensate wells with stand-alone sand screens in 1.65 g/cm3 / 13.8 lb/gal cesium/potassium formate drilling fluids in the Tune reservoir (131°C / 267°F). Wells were drilled horizontally through the reservoir and completed in openhole with 300-micron single-wire-wrapped screens. Section lengths were 350–900 m / 1,150–2,950 ft. The lower completions were run in formate drilling fluid and upper completions in clear cesium/potassium formate brine. Cesium/potassium formate brine was then used to suspend the wells for 6 to 12 months. The wells and the residual filter-cake lining the open boreholes cleaned up naturally during the early production phase. No filter-cake removal or well stimulation treatments were required.
  • References: Field Case Study, TuneSPE 130376SPE 145562

BP: High Island, USA, Completion and Kill Fluid

  • Year: 2002
  • Application: Completion
  • Density: 2.11 g/cm3 / 17.6 lb/gal
  • Temperature: 177°C / 350°F
  • Description: An HPHT (177°C /350°F, 14,000 psi) well needed recompletion after S13Cr tubing failed due to stress corrosion cracking from exposure to calcium chloride/calcium bromide packer fluid. The well was recompleted with 2.11 g/cm3 / 17.6 lb/gal cesium/potassium formate brine. Sodium formate brine was successfully left in the anulus as packer fluid for six years.
  • References: OTC 24983; Formate Matters Newsletter #4

BP: Devenick, UK North Sea, Drilling and Completion

  • Year: 2001 and 2002
  • Application: Coring, drilling, pre-drilled liner completion fluid
  • Density: Up to 1.78 g/cm3 / Up to 14.9 lb/gal
  • Temperature: 154°C / 310°F
  • Description: Two horizontal HPHT wells were drilled with 1.66–1.78 g/cm3 / 13.1–14.9 lb/gal cesium formate fluid. The first job was turbine-motor drilling 385 meters of 6" hole at 88° deviation from a semi-submersible in hard, abrasive low-permeability (1 mD) Brae sandstone. Cesium formate drilling fluid was used in the first well for coring and drilling four intervals, LWD/wireline logging and the lower completion (well was open for six days). The lower completion comprised of 4 1/2" liners, JMZX packer and a FIV liner-top isolation valve. The upper completion was run in clear 1.65 g/cm3 / 3.1 lb/gal cesium/potassium formate brine.
  • References: OTC 15322

Norsk Hydro/Statoil: Visund/Visund Sør, Norway North Sea, Completion

  • Year: 2001 - present
  • Application: LSOBM, perforation fluid
  • Density: 1.78 g/cm3 / 14.9 lb/gal
  • Temperature: 121°C / 250°F
  • Description: Norsk Hydro used 1.65 g/cm3 / 13.8 lb/gal LSOBM (low-solids oil-based mud) with cesium formate as the internal phase to perforate several oil wells. Production rates increased by 600% compared with previous attempts to perforate in calcium bromide brine. In recent years, several wells have been perforated overbalanced in cesium/potassium formate fluid-loss pills.
  • References: SPE 73709; SPE 83696; SPE 84910; SPE 87126; Presentation, Low Solids Oil Based Perforation Fluid

Statoil: Huldra, Norway North Sea, Drilling and Completion

  • Year: 2000 - 2002
  • Application: Drill-in, openhole sand screen
  • Density: Up to 1.94 g/cm3 / Up to 16.2 lb/gal
  • Temperature: 149°C / 300°F
  • Description: Six HPHT wells were drilled and completed with 1.89–1.94 g/cm3 / 15.8–16.2 lb/gal cesium/potassium formate brine. The wells were up to 5,700 m deep, with reservoir sections of 264 to 344 m. Reservoir sections were drilled at 45° to 57° inclination and completed with stand-alone sand screens.
  • References: Field Case Study, Statoil Huldra; SPE 189530

Elf/Total E&P: Elgin/Franklin, UK North Sea, Compeltion and Kill Fluid

  • Year: 1999-2015
  • Application: Workover, intervention, suspension, P&A, lower completion, stuck pipe/well kill (standby fluid)
  • Density: 2.25 g/cm3 / 18.7 lb/gal
  • Temperature: Up to 205°C / Up to 401°F
  • Description: High-density cesium formate brine provided effective well control in almost 30 completion, workover and suspension operations in Elgin/Franklin HPHT fields (190–205°C / 374–401°F, 110 MPa / 15,954 psi). Two perforated wells were suspended in cesium formate brine for 15 months and two years respectively. The West Franklin field was the deepest, hottest and highest pressure commercial reservoir in the world when the operations took place. Cesium formate was also regularly held onboard as contingency stuck-pipe release pills and kill-weight pills during operations. 
  • References: Field Case Study, Elgin Franklin; SPE 74541

TotalFina: Dunbar, UK North Sea, Completion

  • Year: 1999
  • Application: Completion, perforation fluid
  • Density: 1.90 g/cm3 / 15.9 lb/gal
  • Temperature: 185°C / 365°F
  • Description: An extended reach (7,353 m / 24,118 ft, 78°) HPHT well was perforated in high-density cesium/potassium formate brine. In terms of length and horizontal displacement, the well was a record for TotalFina. Cesium/potassium formate brine was selected for completion after several unsuccessful attempts with another fluid.

Shell Expro: Shearwater, UK North Sea, Completion

  • Year: 1999-2008
  • Application: Workover, perforation fluid
  • Density: Up to 2.06 g/cm3 / Up to 17.2 lb/gal
  • Temperature: 185°C / 365°F
  • Description: Shell Expro used 1.80–2.06 g/cm3/15.0–17.2 lb/gal cesium/potassium formate brine to work over four wells in the HPHT Shearwater field from 1999 to 2003. One of the wells was perforated underbalanced in the formate brine. In 2008, another workover operation was carried out on one Shearwater well using cesium/potassium formate brine.
  • References: Field Trial Success Article; SPE 165151