Classifications

• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
  • C09K8/00—Compositions for drilling of boreholes or wells; Compositions for treating boreholes or wells, e.g. for completion or for remedial operations
  • C09K8/02—Well-drilling compositions
  • C09K8/32—Non-aqueous well-drilling compositions, e.g. oil-based
  • C09K8/34—Organic liquids

Definitions

• the present invention relates to a drilling fluid particularly suitable for drilling in deep offshore (deep sea), that is to say, drilling under particularly difficult temperature conditions deep.
• deep sea deep offshore
• the present invention also relates to drilling mud comprising said fluid, and the use thereof.
• the drilling fluids are used in the composition of drilling muds at a level of 30 to 95% by weight. These drilling muds play an essential role during on-shore or off-shore drilling operations, since they make it possible to lubricate the drill bit (or trephine) to limit its wear, but also to go back to the surface for treatment, the cuttings Rock
• Drilling mud is usually stored on the surface of the well to be pumped.
• Drilling muds have very complex formulations depending on the nature of the formations traversed, depth, geometry, pressure conditions, temperature, and other characteristics of the well.
• drilling muds There are two primary categories of drilling muds: sludge and oil sludge.
• the drilling fluid In water sludge (WBM or Water Base Mud), the drilling fluid is water, so they remain reserved for low-tech applications and drilling onshore (onshore), or off shore very little deep (a few meters).
• WBM or Water Base Mud oil sludge
• OBM or OiI Base Mud oil sludge
• the drilling fluid is a hydrocarbon fluid selected from various compounds available on the market.
• Group I comprises the strongly aromatic drilling fluids containing from 5 to 30% monoaromatic and / or aromatic polyes from the refining of crude oils, that is to say gas oils and conventional mineral oils.
• Group II includes moderately aromatic drilling fluids from crude oil refining and containing 0.5 to 5% monoaromatic and / or polyaromatic compounds such as unconventional or weakly hydrotreated mineral oils often referred to as LTMO (Lo w Toxicity Minerals OiI or mineral oil with low toxicity).
• LTMO Lo w Toxicity Minerals OiI or mineral oil with low toxicity
• Group III includes low aromatic drilling fluids, that is to say containing less than 0.5% of total aromatics of which less than 10 ppm of polyaromatics.
• These fluids are derived from chemical syntheses, or refined sections severely hydrotreated, hydrocracked or hydroisomerized. They can also be composed of synthetic paraffins resulting from the Fisher Tropsch process, of polymerized olefins (Olefins or Olefins, Linear Olefins or LAO, and
• Group III fluids are termed synthetic according to the definition of the OSPAR Protocol by Decision 2000/3 "On the Use of Organic-Phase Drilling Fluids" (OPF) and the Discharge of OPF-Contaminated Cuttings.
• OPF Organic-Phase Drilling Fluids
• These Group III fluids are preferred by operators not only for their thermal stability, their resistance to oxidation, for their low toxicity due to their low aromaticity, for their non-irritating and environmentally friendly nature, but also for their compliance with security requirements by a high flash point and lower volatility.
• hydrocarbon vapors of the drilling fluid suspended in the ambient air can reach significant concentrations around the vibratory mud recovery screens, and around Sludge storage and treatment points.
• the operators present for the drilling operations may be in contact with the sludge containing these fluids, either by dermal contact or by inhalation. This personnel may thus be exposed to concentrations of vaporized hydrocarbon products greater than 450 mg / m3. In Norway, the authorities
• the temperature of the sludge at the outlet of the well and its flow rate will influence the amount of steam in the work area and therefore, the level of exposure of the operators.
• Knowing the rate of volatility of the drilling fluid is therefore essential for controlling impacts on the health and safety of operators. Nevertheless, this volatility remains difficult to quantify, especially for low volatile hydrocarbon fluids. However, this criterion of volatility is important only at the moment of the return of the mud on the surface, and the mud must above all have all the characteristics required so that the drill bit at the bottom of the well does not wear too fast or is blocked not.
• a good cold rheology between -10 0 C and -20 0 C is to achieve a good viscosity at these temperatures while maintaining the other characteristics equal.
• hydrocarbons have the disadvantage of being also very volatile, which increases the risks related to the safety and health of users at the return to the wellhead where the temperature of the sludge reaches more than 60 ° C.
• fluids of very low viscosity for example of kinematic viscosity at 40 ° C. of less than 2.5 mm 2 / s according to ISO 3104 or ASTM D445, in the case of deep wells in order to limit energy losses by friction, mainly at the level of drill stem, in order to reduce the drilling time.
• the aromatic diesel cuts from distillation distillate distillation distillates between 250 and 380 ° C. have a viscosity at 40 ° C. determined according to the ISO 3104 standard of US Pat. order of 3 mm 2 / s for a volatility at 100 ° C. of 10 mbar (l KPa).
• These fluids are less and less used because their toxicity is high because of their high aromatic content, higher than 10%, which makes them unsuitable for offshore drilling since it contradicts the environmental regulations of most countries.
• drilling fluids based kerosene cuts weakly treated hydro on the market and whose viscosity ranges from 1.7 to 1.9 mm 2 / s for a volatility of 20 to 25 mbar (2 to 2.5 KPa). If the viscosity at 40 ° C. is good, these fluids are very volatile, which goes against the environmental and safety rules.
• Drillers use but less systematically hydrocarbons with n-paraffins: their viscosity varies from 1.5 to 2 mm 2 / s, while their volatility remains above 11 mbar (ll KPa): their pour point close to 0 0 C (ASTM D97), and their viscosity at very low temperature (kinematic viscosity at 0 0 C above 12 cSt according to
• the patent WO 97/34963 recommends the use as drilling fluids of the hydro-carbon cuts obtained by GTL or gas to liquid transformation, of a synthesis gas, after hydrocracking and hydroisomerization of the product obtained.
• This document recommends the use of non-toxic, non-polluting and biodegradable drilling fluids, these fluids being composed of a mixture of n-paraffins from ClO to C24 and of isoparaffmes, the isoparaffmes-n-paraffin ratio varying from 0.5: 1 to about 9: 1, the isoparaffins containing more than 50% by weight of monomethylated species based on the total weight of the isoparaffins present in the mixture.
• the viscosity characteristics at 40 0 C are acceptable nothing is said about the volatility of these cuts.
• the object of the present invention is here to have a drilling fluid having the best compromise in terms of viscosity and volatility. It aims in particular to obtain a fluid whose characteristics have the best compromise between a viscosity at 40 ° C. always less than 2.5 mm 2 / s and a volatility calculated according to the VPtool protocol characterized by a vapor pressure at 100 ° C. C always less than 10 mbar (l KPa).
• the subject of the present invention is therefore a drilling fluid having a viscosity at 40 ° C. of less than or equal to 2.5 mm 2 / s and a vapor pressure at 100 ° C.
• the fluid has a kinematic viscosity at 40 ° C. of less than 2.3 mm 2 / s.
• the Applicant has used a calculation model perfectly correlated with the VPTool tool, having the advantage of calculating the vapor pressure of a hydrocarbon fluid between 0 and 200 ° C from its physico-chemical characteristics and its composition.
• this fluid is a good compromise for balancing viscosity and vapor pressure, it also has good properties for the additives generally used in drilling muds, and especially a good cold resistance, linked to a point of contact. low flow, but also low toxicity due to its very low aromatics content, significant biodegradability, greater than 60% according to the OECD 306 protocol and excellent ecotoxicological properties (compatible with OSPAR regulations).
• this fluid comprises hydro carbon cuts obtained by direct distillation of the crude oils, the distillates being subsequently hydrocracked and / or hydrotreated, or even hydrodewaxed.
• These fluids may optionally be used in admixture with vegetable oil esters in concentration ratios of 10/90 to 90/10.
• hydrotreatment it is intended to desulphurize and / or de-aromatised the rate of desulphurization and or déaroamtisation can be very high.
• these fluids have an aromatic content of less than 500 ppm and a sulfur content of less than 50 ppm.
• the aromatic content will be less than 100 ppm and the sulfur content less than 10 ppm.
• This fluid is obtained from hydrocarbons of the group consisting of jets and kerosene strongly deflavored and desulfurized pour point below -20 0 C measured according to ASTM D97.
• These fluids are composed of more than 25% of isoparaffins and less than 45% of n-paraffins and less than 500 ppm of aromatics. More particularly, fluids containing 25 to 70% isoparaffins and 5 to 45% n-paraffins and less than 100 ppm aromatics are selected. Typically, these fluids contain a concentration of naphthenes between 20 and 40% by weight, preferably between 25 and 35% by weight of the fluid. These fluids can be used alone or in combination with fluids of the prior art if the final characteristics of the compound fluid respect the characteristics of viscosity and calculated volatility, and pour point, object of the invention.
• Another object of the invention is the use of this fluid in the manufacture of drilling mud, oil sludge and / or water sludge.
• the drilling mud will comprise more than 30% of the drilling fluid.
• functional additives depending on the type of application of the sludge.
• One of the main functional additives of sludge or fluid is the weighting agent essentially consisting of barite.
• Other additives may be used in combination which are emulsifiers, wetting agents, viscosifiers, filtrate reducing agents, particulate agents for forming the gravel filters, proppants for maintaining hydraulically open fractures in subterranean formations, such as cellophane, scleroglucan and xanthan.
• compositions of these sludges obtained from fluids according to the invention will vary according to whether they will be used as buffer fluid, as drilling mud or as fracturing fluid of the underground formations.
• this drilling mud will consist of 30% to
• a third object of the invention is the use of the sludge containing from 30 to 95% of the fluid according to the invention for drilling at sea at depths of more than 2000m, preferably of more than 4000m, for the drilling of wells also of more than 2000m, preferably more than 4000m, these wells being conventional wells, horizontal or deviated.
• This sludge can be used as a buffer fluid, as a drilling mud or as a fracturing fluid for subterranean formations.
• the present example aims to compare the characteristics of the fluids according to the invention hereinafter designated Di with those usually used referenced Ti.
• Vp The values of Vp were calculated using the VP Tool tool at 100 ° C.

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• Chemical & Material Sciences (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Life Sciences & Earth Sciences (AREA)
• General Life Sciences & Earth Sciences (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Organic Chemistry (AREA)
• Lubricants (AREA)
• Earth Drilling (AREA)
• Excavating Of Shafts Or Tunnels (AREA)

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Citations (4)

• 2009
  • 2009-04-15 FR FR0901830A patent/FR2944528B1/fr not_active Expired - Fee Related
• 2010
  • 2010-04-14 BR BRPI1006712-4A patent/BRPI1006712B1/pt active IP Right Grant
  • 2010-04-14 US US13/264,000 patent/US20120028854A1/en not_active Abandoned
  • 2010-04-14 CA CA2758655A patent/CA2758655C/fr active Active
  • 2010-04-14 EP EP10717786.7A patent/EP2419487B1/fr active Active
  • 2010-04-14 JP JP2012505285A patent/JP5759978B2/ja active Active
  • 2010-04-14 ES ES10717786.7T patent/ES2527331T3/es active Active
  • 2010-04-14 WO PCT/IB2010/051625 patent/WO2010119413A1/fr not_active Ceased

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