GAS EVOLVING OIL VISCOSITY DIMINISHING COMPOSITIONS FOR STIMULATING THE PRODUCTIVE LAYER OF AN OIL RESERVOIR

• US 20110203797A1
• Filed: 10/15/2008
• Published: 08/25/2011
• Est. Priority Date: 10/15/2008
• Status: Active Grant

• Current Assignee: Viscos Energy Holding AG
• Original Assignee: Tctm (Hong Kong) Limited
• Inventors: Koller, Zdenek, Alexandrov, Eugeny Nikolaevich, Lemenovski, Dmitry Anatoljevich
• Granted Patent: US 8,387,697 B2
• Time in Patent Office: Days
• US Class Current: 166/300
• CPC Class Codes: C09K 8/58 Compositions for enhanced recovery methods for obtaining hydrocarbons, i.e. for improving the mobility of the oil, e.g. displacing fluids
• CPC Class Codes: C09K 8/92 characterised by their form or by the form of their components, e.g. encapsulated material C09K8/70 takes precedence
• CPC Class Codes: E21B 17/18 Pipes provided with plural fluid passages E21B17/203 takes precedence
• CPC Class Codes: E21B 36/008 using chemical heat generating means
• CPC Class Codes: E21B 43/24 using heat, e.g. steam injection
• CPC Class Codes: E21B 43/243 Combustion in situ

Abstract

The invention is directed to a chemical system of gas evolving oil viscosity diminishing compositions (GEOVDC) for stimulating the productive layer of an oil reservoir, that is to chemical compositions for a thermochemical treatment of an oil reservoir, more specifically for initiating a chemical reaction in the productive layer zone of the oil reservoir to produce heat and evolve gases so that the extraction of oil (petroleum) is improved. The invention is further directed to a method of thermochemically treating an oil reservoir by means of this chemical system, and to an apparatus for performing thermochemical treatment of an oil reservoir.

Claims

1-42. -42. (canceled)

43. A chemical system for thermally treating an oil reservoir by initiating a chemical reaction in a pay zone of said oil reservoir, wherein said chemical system comprises at least the following two compositions:

a thermal gas emitting composition (TGEC) being an aqueous solution or suspension comprising at least one compound selected from the group consisting of hydrazine nitrate, 1,1-di C_2-6 alkyl hydrazine nitrates and 1,2-di C_2-6 alkyl hydrazine nitrates, such as 1,1-dimethyl hydrazine nitrate or 1,2-dimethyl hydrazine nitrate, guanidine nitrate, formamide nitric acid adduct, acetamide nitric acid adduct, acetonitrile nitric acid adduct, urea nitric acid adduct, ammonium nitrate, potassium nitrate, sodium nitrate, calcium nitrate, mono, di and tri C_1-5 alkyl amine nitrates, mono, di and tri C_1-5 alkanol amine nitrates, C_2-6 alkylene diamine mono and dinitrates and poly C_1-5 alkylene polyamine polynitrates; and

a reaction initiator stabilizer (RIS) being a liquid solution or suspension and comprising at least one compound selected from the group consisting of;

metal borohydrides MBH₄, wherein M is Li, Na or K;

aminoboranes (R¹R²R³)N.BH₃, wherein R¹, R² and R³ are independently hydrogen or C_1-10 alkyl, or wherein R¹ is an aryl or pyridine with up to 10 carbon atoms and R² and R³ are hydrogen;

dialkylaluminates MAlH₂R¹R², wherein M is Li, Na or K, and R¹ and R² are independently C_1-10 alkyl;

aminoalanes (R¹R²R³)N.AlH₃, wherein R¹, R² and R³ are independently hydrogen or C_1-10 alkyl; and

aluminum or aluminum alloys with magnesium,

wherein the TGEC or the RIS additionally contain at least one soluble salt selected form the group consisting of Mn, Fe, Cr, Co, Ni or V.

44. The chemical system of claim 43, wherein the TGEC is the reaction product of reacting nitric acid with a respective amino compound.

45. The chemical system of claim 43, wherein the pH of the TGEC is about 3 to 14.

46. The chemical system of claim 43, wherein the RIS is a solution or suspension in an appropriate solvent.

47. The chemical system of claim 46, wherein the solvent for the RIS is water or an organic solvent selected from the group consisting of petrol, ligroin, white spirit, kerosene and naphtha.

48. The chemical system of claim 43, wherein the aluminum or aluminum alloys with magnesium are fine dispersed, phrophoric or granular.

49. A method of thermally treating an oil reservoir by initiating a chemical reaction in a pay zone of said oil reservoir, using a chemical system comprising at least the following two compositions:

a thermal gas emitting composition (TGEC) being an aqueous solution or suspension comprising at least one compound selected from the group consisting of hydrazine nitrate, 1,1-di C_2-6 alkyl hydrazine nitrates and 1,2-di C_2-6 alkyl hydrazine nitrates, such as 1,1-dimethyl hydrazine nitrate or 1,2-dimethyl hydrazine nitrate, guanidine nitrate, formamide nitric acid adduct, acetamide nitric acid adduct, acetonitrile nitric acid adduct, urea nitric acid adduct, ammonium nitrate, potassium nitrate, sodium nitrate, calcium nitrate, mono, di and tri C_1-5 alkyl amine nitrates, mono, di and tri C_1-5 alkanol amine nitrates, C_2-6 alkylene diamine mono and dinitrates and poly C_1-5 alkylene polyamine polynitrates; and

a reaction initiator stabilizer (RIS) being a liquid solution or suspension and comprising at least one compound selected from the group consisting of;

metal borohydrides MBH₄, wherein M is Li, Na or K;

aminoboranes (R¹R²R³)N.BH₃, wherein R¹, R² and R³ are independently hydrogen or C_1-10 alkyl, or wherein R¹ is an aryl or pyridine with up to 10 carbon atoms and R² and R³ are hydrogen;

dialkylaluminates MAlH₂R¹R², wherein M is Li, Na or K, and R¹ and R² are independently C_1-10 alkyl;

aminoalanes (R¹R²R³)N.AlH₃, wherein R¹, R² and R³ are independently hydrogen or C_1-10 alkyl; and

aluminum or aluminum alloys with magnesium,

wherein said thermal gas emitting composition (TGEC) and said reaction initiator stabilizer (RIS) are separately introduced into said oil reservoir and are contacted in the pay zone of said oil reservoir to initiate a chemical reaction producing heat and gases, and wherein the TGEC is continuously introduced into the oil reservoir and the RIS is introduced simultaneously and in a continuous or intermittent way into the oil reservoir.

50. The method of claim 49, wherein the introduction of the TGEC and the RIS is continued during the chemical reaction to maintain a continuous reaction.

51. The method of claim 49, wherein the TGEC is the reaction product of reacting nitric acid with a respective amino compound.

52. The method of claim 49, wherein the pH of the TGEC is about 3 to 14.

53. The method of claim 49, wherein the RIS is a solution of suspension in the appropriate solvent.

54. The method of claim 53, wherein the solvent of the RIS is water or an organic solvent selected from the group consisting of petrol, ligroin, white spirit, kerosene and naphtha.

55. The method of claim 49, wherein the aluminum or aluminum alloys with magnesium are fine dispersed, pyrophoric or granular.

56. The method of claim 49, wherein the TGEC or the RIS additionally contain at least one soluble salt selected form the group consisting of Mn, Fe, Cr, Co, Ni or V.

57. The method of claim 49, wherein the TGEC and RIS are pumped into the oil reservoir with a rate of about 4-8 liters per second.

58. The method of claim 49, comprising the steps:

(a) introducing granules of aluminum or an aluminum/magnesium alloy as the RIS into an oil well of said oil reservoir and keeping said granules in a reaction chamber located in the oil well;

(b) introducing the TGEC into the oil well so that it contacts said granules kept in the reaction chamber for initiating and maintaining a thermochemical reaction producing heat and gases;

(c) passing the produced hot gases into the pay zone of the oil reservoir;

(d) shifting the thermochemical reaction into the pay zone of the oil reservoir by allowing said granules to enter into the pay zone; and

(e) contacting the granules in the pay zone with the TGEC introduced into the oil well.

59. The method of claim 58, wherein said reaction chamber is located in or adjacent to the pay zone of the oil reservoir.

60. The method of claim 58, wherein urea nitric acid adduct is used as the TGEC.

61. The method of claim 58, wherein the pH value in the reaction chamber is about 3-4 and wherein hydrogen gas produced by the thermochemical reaction is oxidized by H₂O.

62. The method of claim 58, wherein the thermochemical reaction and thus the granules are shifted into fractures present in the pay zone.

63. The method of claim 58, wherein the thermochemical reaction is shifted into the pay zone after the pay zone is heated to about 300°

C.

64. The method of claim 58, wherein the granules in the pay zone are additionally contacted with at least one strong oxidizing agent such as potassium dichromate K₂Cr₂O₇.

65. The method of claim 58, wherein petroleum in the oil reservoir is subjected to a hydrocracking process.

66. The method of claim 49, wherein the TGEC and RIS are introduced in the form of fluid layers separated by layers of a spacer fluid.

67. The method of claim 49, comprising the steps:

(a) introducing granules of aluminum or an aluminum/magnesium alloy as the RIS into an oil well of said oil reservoir and keeping said granules in a first reaction chamber located in the oil well;

(b) introducing a first TGEC into the oil well so that it contacts said granules kept in said first reaction chamber for initiating and maintaining a thermochemical reaction producing thermal energy and heating up the walls of said first reaction chamber;

(c) introducing a second TGEC into the oil well such that it comes in contact with the heated walls of said first reaction chamber and is ignited;

(d) passing the ignited TGEC to a second reaction chamber where the TGEC reacts under production of heat and gases; and

(e) passing the produced hot gases into the pay zone of the oil reservoir.

68. An apparatus for performing thermochemical treatment of an oil reservoir by separately introducing a thermal gas emitting composition (TGEC) and a reaction initiator stabilizer (RIS) into an oil well of said oil reservoir and contacting the TGEC and RIS in a pay zone of said oil well for initiating and maintaining a chemical reaction producing heat and gases, wherein the apparatus comprises:

an outer tubing inserted in a casing of the oil well such that an outer annular space between the outside of the outer tubing and the inside of the casing is provided, wherein the lower end of the outer tubing is located in or above the pay zone of the oil well;

a packer being positioned above the lower end of the outer tubing and sealing the outer annular space;

an inner tubing inserted in said outer tubing, such that an inner annular space between the outside of the inner tubing and the inside of the outer tubing is provided, wherein the inner tubing allows the supply of one of the TGEC or RIS to the pay zone and the inner annular space allows the supply of the other one of the TGEC or RIS to the pay zone, and wherein the lower end of the inner tubing is located in or above the pay zone;

wherein at least one of the lower end of the outer tubing and the lower end of the inner tubing is located in the pay zone of the oil well; and

a mixing device contacting the TGEC and the RIS in the pay zone of said oil well.

69. The apparatus of claim 68, wherein the mixing device is embodied by:

a sealed lower end of the outer tubing being located above the lower end of the inner tubing but below the packer; and

openings in the inner tubing allowing a fluid exchange between the inner annular space and the inner tubing, wherein said openings are located at a distal section of the inner tubing but above the lower end of the outer tubing.

70. The apparatus of claim 69, wherein said openings are slot jet nozzles embodied by tubular connecting passages extending diagonal through the inner tubing and comprising a slot.

71. The apparatus of claim 70, wherein said slots are formed in a lower half of the tubular connecting passages.

72. The apparatus of claim 69, wherein below the openings in the inner tubing a beaker is inserted in the inner tubing, said beaker comprises openings in its bottom allowing the passage of the mixed fluids but not of granular material supplied with the RIS through the inner tubing.

73. The apparatus of claim 72, wherein said beaker is made of aluminum or an aluminum/magnesium alloy.

74. The apparatus of claim 68, wherein below the openings in the inner tubing at least one turbine mixing device is arranged in the inner tubing, said turbine mixing device comprises a shaft supported by means of at least one plain bearing and carrying turbine vanes and mixing vanes, wherein the plain bearing comprises openings allowing the passage of the fluids flowing through the inner tubing and wherein the turbine vanes transmit energy from the flowing fluids to the shaft to rotate the shaft with the attached mixing vanes.

75. The apparatus of claim 68, wherein the mixing device is embodied by:

the lower end of the inner tubing being located above the lower end of the outer tubing; and

at least one turbine mixing device being arranged in the outer tubing below the lower end of the inner tubing, said turbine mixing device comprising a shaft supported by means of at least one plain bearing and carrying turbine vanes and mixing vanes, wherein the plain bearing comprises openings allowing the passage of the fluids flowing through the inner tubing and wherein the turbine vanes transmit energy from the flowing fluids to the shaft to rotate the shaft with the attached mixing vanes.

76. The apparatus according to claims 73, wherein consecutive turbine mixing devices have opposite directions of rotation.

77. The apparatus of claim 68, wherein the mixing device is embodied by:

the lower end of the inner tubing being located above the lower end of the outer tubing; and

a beaker inserted in the lower end of the inner tubing, said beaker comprises openings in its bottom allowing the passage of the fluids supplied through the inner tubing except the granular material supplied with the RIS.

78. The apparatus of claim 77, wherein the mixing device is made of aluminum or an aluminum/magnesium alloy.

81. The apparatus of claim 68, wherein the packer comprises sensing elements for measuring the temperature of the packer and the pressure under the packer.

82. The apparatus of claim 68, wherein the mixing device further comprises at least one reaction chamber in which the TGEC and RIS are reacted.

79. An apparatus for performing thermochemical treatment of an oil reservoir by separately introducing a thermal gas emitting composition (TGEC) and a reaction initiator stabilizer (RIS) into an oil well of said oil reservoir and contacting the TGEC and RIS in a pay zone of said oil well for initiating and maintaining a chemical reaction producing heat and gases, wherein the apparatus comprises:

a tubing inserted in a casing of the oil well such that an annular space between the outside of the tubing and the inside of the casing is provided, wherein a lower end of the tubing is located in or above the pay zone of the oil well;

a packer positioned above the lower end of the tubing and sealing the annular space; and

a beaker inserted in the lower end of the inner tubing, said beaker comprises openings in its bottom allowing the passage of the fluids supplied through the inner tubing except the granular material supplied with the RIS.

80. The apparatus of claim 79, wherein the mixing device is made of aluminum or an aluminum/magnesium alloy.