Classifications

• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
  • C11D1/00—Detergent compositions based essentially on surface-active compounds; Use of these compounds as a detergent
  • C11D1/38—Cationic compounds
  • C11D1/52—Carboxylic amides, alkylolamides or imides or their condensation products with alkylene oxides
  • C11D1/526—Carboxylic amides (R1-CO-NR2R3), where R1, R2 or R3 are polyalkoxylated
• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
  • C11D1/00—Detergent compositions based essentially on surface-active compounds; Use of these compounds as a detergent
  • C11D1/38—Cationic compounds
  • C11D1/52—Carboxylic amides, alkylolamides or imides or their condensation products with alkylene oxides
  • C11D1/523—Carboxylic alkylolamides, or dialkylolamides, or hydroxycarboxylic amides (R1-CO-NR2R3), where R1, R2 or R3 contain one hydroxy group per alkyl group
• • E—FIXED CONSTRUCTIONS
  • E21—EARTH DRILLING; MINING
  • E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
  • E21B21/00—Methods or apparatus for flushing boreholes, e.g. by use of exhaust air from motor
  • E21B21/06—Arrangements for treating drilling fluids outside the borehole
  • E21B21/068—Arrangements for treating drilling fluids outside the borehole using chemical treatment
• • E—FIXED CONSTRUCTIONS
  • E21—EARTH DRILLING; MINING
  • E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
  • E21B41/00—Equipment or details not covered by groups E21B15/00 - E21B40/00
  • E21B41/005—Waste disposal systems

Definitions

• the present invention relates to methods of cleaning oil/rock mixtures in oil drilling operations and especially to cleaning of drilling oil from rock cuttings on offshore drilling rigs, removal of oil from the face of newly drilled holes prior to reinforcement with casing, and to the cleaning of oil muds from drilling rigs.
• drilling fluid or drilling mud In the process of drilling for oil and gas, it is necessary for a number of reasons, to use a drilling fluid or drilling mud.
• the types of drilling fluid or mud in common use are:-
• Oil based drilling media (b) may also contain water in the form of water in oil emulsion. It is. customary in the art to refer to a drilling medium containing up to about 15% aqueous phase by volume as oil based. Those drilling media referred to as invert fluids or muds, (c) generally contain between 15% and 55% water. This patent application is particularly concerned with types (b and c) both of which are included in the term "oil” as used herein, together with crude and refined mineral oils.
• drilling fluid One of the functions of drilling fluid is to carry drill cuttings from the drill bit to the surface, the cuttings are then removed by physical techniques, for example, by using shale shakers, screens, cyclones, and centrifuges. After removal of the cuttings the drilling fluid is re-used and the cuttings are disposed of. If the drilling is offshore then the cuttings are disposed of into the sea, where in the case of aqueous drilling fluids the cuttings disperse and settle without causing significant problems.
• the cuttings are oil wet and settle rapidly to the sea bed below the drilling rig and form an oily, sticky mass, which can interefere with drilling operations, for example, by hindering the movement of divers involved in sub-sea construction and maintenance work. It is thought that the swelling of clays in the cuttings is responsible for the formation of this mass. In addition, the cuttings cause oil pollution through gradual release of the oil.
• One technique to remove oil from cuttings is to wash the cuttings with a solvent such as diesal, this has the effect of removing most of the oil but still leaves the surface contaminated with hydrocarbons, which can gradually be released to the environment.
• Another way is to use a water miscible solvent, such as a glycol ether, but these are expensive.
• Yet another way is to wash the cuttings in sea water using good agitation to dislodge the oil from the surface of the cuttings. This process. can be used either as the sole process for removing the drilling oil from the cuttings, or as a second step to remove an oil solvent frcm cuttings previously washed with a hydrocarbon.
• This process can be improved by adding a surfactant to the sea water, to lower the oil/water interfacial tension.
• the cuttings may then be discharged to the sea where they disperse and settle over a wide area of sea bed rather than accurate directly in the area of the drilling operations.
• the oil in water emulsion which is forned as a result of washing the cuttings may be discharged to the sea where fine dispersion of the oil will facilitate its breakdown by micro-organisms.
• a commonly used surfactant for the foregoing purposes is a C 9-11 alcohol six mole ethoxylate.
• An object of the present invention is to provide more effective methods of cleaning oil frcm rock cuttings.
• a further object of our invention is to provide a method whereby oil can be separated from the emulsion resulting from cleaning of the cuttings.
• our invention provides a method of cleaning which comprises contacting an oil coated rock with an aqueous solution containing an affective amount of a mixture of (A) from 5 to 95% by weight of at least one alkoxylated alcohol, carboxylic acid, alkylphenol, or nonionic phosphate ester, having in each case at least one alkyl group with from 6 to 22 carbon atoms and from 1 to 20 ethyleneoxy groups, with (B) from 95 to 5% by weight of at least one alkanolamide of the formula:- wherein R is a saturated or unsaturated alkyl group, having from 5 to 17 carbon atoms and x and y are each chosen from 0 and integers from 1 to 12, such that x - y is from 1 to 12.
• (A) is primary straight or branched chain alcohol having from. 6 to 18 carbon atoms and alkoxylated with from 1 to 10 ethylene-oxy groups.
• a mixture of (A) and (B) is supplied as a concentrate which is dissolved in, or diluted with, water to provide the cleansing solution at the site of the rig.
• Such concentrates optionally contain a solvent such as water or a water miscible alcohol, glycol or glycol ether, e.g. isopropanol, ethylene glycol, propylene glycol, polyethylene glycol, as required to provide a fluid, pourable composition under the conditions likely to be encountered.
• the concentrate may, additionally, contain minor proportions of hydrotropes, such as alkaline earth, sodium potassium mono- di- or tri- alkyl benzene sulphonate salts having less than six aliphatic carbon atcms, e.g.
• toluene or xylene sulphonates phosphate esters salts
• preservatives such as formalin, dyes and/or perfumes.
• Water may be present in any convenient proportion between zero and the final working concentration of the cleaner. Generally, the lower the proportion of the water the greater the convenience for transport and storage of the concentrate. These considerations however must be balanced against the preference for a stable, pourable composition.
• Organic solvents can add appreciably to the cost of the composition and are preferably, therefore used sparingly e.g. less than 50% and preferably less than 20% of the weight of the concentrate.
• the concentrate may typically contain from 5 to 95% by weight of (A) and from 95 to 5% by weight of B.
• (A) is present in concentrations greater than 10% by weight, most preferably greater than 20% and usually greater than 30%.
• (B) is also preferably present in concentrations of greater than 10% by weight, more preferably greater than 20% and usually greater than 30%.
• a suitable mixture contains from 40% to 60% of (A), from 60% to 40% of (B) and from 0 to 20% of solvent.
• the concentrate is dissolved or dispersed in water at the site of application. When used at offshore locations, the concentrate may conveniently be dissolved or dispersed in sea water. Typically, the concentrate is diluted to from 0.5% to 10% active matter by weight preferably from 1 to 5. We do not exclude higher concentrations, but they are unlikely to prove cost effective. - Concentrations below 0.5% are not excluded but are only marginally effective.
• the cuttings When used to clean rock cuttings, the cuttings are preferably agitated with the solution of the concentrate in water or brine, for a sufficient time to emulsify a substantial proportion of the oil.
• the emulsion may then be separated from the cuttings which, when sufficiently clean, are dumped.
• the emulsion may be discharged.
• the oil is recovered from the emulsion by moderate heating. Typically temperatures in excess of 40°C e.g. 50 to 70°C are sufficient to break the emulsion and permit recovery of the separated oil phase.
• the cleaning solution according to our invention may also be injected into bore holes to clean oil frcm the sides of the rock. This is necessary when a casing is to be bonded with cement to the sides of the bore hole.
• the solution may also be used according to our invention to clean oil mud from the rigs themselves and generally to remove viscous hydrocaroon oils from hard surfaces.
• the weight of oil left on the cuttings expressed as a percentage of weight of dry cuttings - weight of oil
• step c) The emulsion decanted in step c) and obtained using A (3.75%) +B (1.25%) was heated to 40°C and seperated into distinct oil and aqueous phases.
• a concentrate was prepared for use according to the invention consisting of 45% by weight of C10 C12 fatty alcohol 5 mole ethoxylate, 45% by weight coconut diethanolamide, 5% by weight propylene glycol, 5% by weight water.
• the product was fluid and stable at temperatures between -5°C and 35°C and readily dispersed in sea water. When evaluated in the above cuttings cleaning test the results were as follows.
• step c) of the method and obtained using the formulation of Example 7 was heated to 50°C and separated into distinct oil and aqueous phases.
• test solution used contained 7.5% of a C10 C12 fatty alcohol 5 mole ethoxylate, 7.5% coconut diethanolamide and 85% water.
• the oil was substantially removed from the surface of the mild steel leaving a clean non-oily surface.
• test solution was a commercial hydrocarbon solvent based degreaser believed to contain emulsifiers.
• the mild steel was less thoroughly cleaned and the surface was oily.

Landscapes

• Engineering & Computer Science (AREA)
• Life Sciences & Earth Sciences (AREA)
• Chemical & Material Sciences (AREA)
• Mining & Mineral Resources (AREA)
• Geology (AREA)
• Environmental & Geological Engineering (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Geochemistry & Mineralogy (AREA)
• Fluid Mechanics (AREA)
• Physics & Mathematics (AREA)
• General Life Sciences & Earth Sciences (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Wood Science & Technology (AREA)
• Organic Chemistry (AREA)
• Mechanical Engineering (AREA)
• General Chemical & Material Sciences (AREA)
• Detergent Compositions (AREA)
• Earth Drilling (AREA)

Applications Claiming Priority (2)

Publications (2)

Family

ID=10527518

Family Applications (1)

Country Status (11)

Cited By (5)

Families Citing this family (8)

Citations (7)

Family Cites Families (1)

• 1982
  • 1982-12-23 GB GB08236665A patent/GB2116579B/en not_active Expired
  • 1982-12-31 IN IN948/DEL/82A patent/IN158886B/en unknown
• 1983
  • 1983-01-04 GR GR70199A patent/GR77136B/el unknown
  • 1983-01-05 PH PH28349A patent/PH19657A/en unknown
  • 1983-01-05 ES ES518812A patent/ES518812A0/es active Granted
  • 1983-01-06 DK DK3483A patent/DK3483A/da not_active Application Discontinuation
  • 1983-01-06 DE DE8383300048T patent/DE3360678D1/de not_active Expired
  • 1983-01-06 IE IE26/83A patent/IE53660B1/en unknown
  • 1983-01-06 NO NO830032A patent/NO830032L/no unknown
  • 1983-01-06 EP EP83300048A patent/EP0084411B1/de not_active Expired
  • 1983-01-07 CA CA000419049A patent/CA1203450A/en not_active Expired

Patent Citations (7)

Also Published As

Similar Documents

Legal Events