METHOD FOR IMPROVING PRODUCTION OF OIL FROM OIL RESERVOIR

Description

FIELD OF THE DISCLOSURE

[0001] The disclosure relates to production of oil, and particularly to production of oil from oil reservoir. The present disclosure further concerns production of steam.

BACKGROUND OF THE DISCLOSURE

[0002] An oil reservoir is a subsurface pool of hydrocarbons contained in porous or fractured rock formations. When recovering oil from oil reservoirs, for example a steam injection is used for stimulating the oil well. In other words, steam injection is used for extracting heavy crude oil from the oil well. Commonly steam injection is applied to oil reservoirs which are relatively shallow and which contain crude oils which are very viscous at the temperature of the native underground formation. The injected steam reduces viscosity of paraffins and asphaltenes tying them to the rock surfaces while steam distillation light crude oil creates a small bank of solvent that can miscibly remove trapped oil.

[0003] Producing steam for steam injection requires a lot of energy and therefore it usually accounts for the largest cost in thermal oil production. Traditionally the steam used for steam injection is produced using natural gas or other fossil fuels. Because of rapid descent in oil price recently, there is a heightened pressure to reduce energy costs in the production of oil.

BRIEF DESCRIPTION OF THE DISCLOSURE

[0004] An object of the present disclosure is to provide a method overcome the above problems.

[0005] The objects of the disclosure are achieved by a method which is characterized by what is stated in the independent claims. The preferred embodiments of the disclosure are disclosed in the dependent claims.

[0006] The disclosure is based on the idea of combusting waste in a furnace for producing heat for the production of steam instead of combusting natural gas or other fossil fuel. Instead of combusting waste, waste can also be gasified in a gasifier for producing combustible gas, and then combustible gas obtained from gasification is combusted in a gas burner for the production of steam. In this case the existing gas burners for combusting natural gas can be used for producing heat from the combustible gas.

[0007] An advantage of the method of the disclosure is that waste can usually obtained for free or reception of waste is even paid for. Therefore the cost of fuel for producing steam for steam injection is reduced significantly.

DETAILED DESCRIPTION OF THE DISCLOSURE

[0008] The disclosure relates to a method for improving production of oil from an oil reservoir. The method comprises the step of providing fuel comprising waste. For example the fuel comprises at least 25 % waste. Preferably the fuel comprises at least 50 % waste. More preferably the fuel comprises at least 75 % waste. Most preferably the fuel comprises at least 90 % waste. According to an embodiment the fuel consists of waste. The more fossil fuel can be replaced with waste, the more fuel costs are reduced.

[0009] The method comprises also the step of combusting fuel in a furnace for producing heat. For example the furnace is a fluidized bed furnace, such as atmospheric fluidized bed furnace, pressurized fluidized bed furnace, bubbling fluidized bed furnace or circulating fluidized bed furnace. The method comprises also the step of producing steam using heat produced in the step of combusting fuel.

[0010] Alternatively the method comprises also the step of gasifying fuel in a gasifier for producing combustible gas. For example the gasifier is a fluidized bed gasifier. In this case the method comprises also the step of combusting combustible gas produced in the step of gasifying fuel in a gas burner for producing heat. The method comprises also the step of producing steam using heat produced in the step of combusting fuel.

[0011] For combusting in a fluidized bed furnace or gasifying in a fluidized bed gasifier, the fuel must be sufficiently fine. Therefore the fuel is adapted to be combusted or gasified in a fluidized bed furnace or in a fluidized bed gasifier. According to an embodiment the step of providing fuel comprises providing waste that has been shredded, dehydrated and screened. According to an embodiment the step of providing fuel comprises steps of providing waste, shredding waste, dehydrating waste and screening waste. In the step of shredding waste the particle size of the waste is made sufficiently small to be suitable for combusting in a fluidized bed furnace. In the step of screening waste particles, that are not suitable for combustion or gasification, are removed.

[0012] The method comprises also the step of feeding steam produced in the step of producing steam to the oil reservoir.

[0013] According to an embodiment the waste as a whole has a positive calorific value. In other words the waste may comprise components that are not combustible, such as metal objects, and thus having no calorific value. However, the waste needs to comprise components that are sufficiently dry for having a positive calorific value.

[0014] According to an embodiment the fuel comprises refuse-derived fuel (RDF). For example RDF is solid recovered fuel (SRF). The classification and specification of SRF has been laid down in EN15359 (standard from the European Standardisation Committee). For example the fuel comprises at least 25 % RDF. Preferably the fuel comprises at least 50 % RDF. More preferably the fuel comprises at least 75 % RDF. Most preferably the fuel comprises at least 90 % RDF. According to an embodiment the fuel consists of RDF.

[0015] According to an embodiment the fuel comprises waste originating from oil drilling or oil refining. Because waste originating from oil drilling or oil refining are readily available at the site of the oil well, no transportation of such waste is required. For example the fuel comprises at least 25 % waste from oil drilling or oil refining. Preferably the fuel comprises at least 50 % waste from oil drilling or oil refining. More preferably the fuel comprises at least 75 % waste from oil drilling or oil refining. Most preferably the fuel comprises at least 90 % waste from oil drilling or oil refining. According to an embodiment the fuel consists of waste from oil drilling or oil refining. According to an embodiment the waste from oil drilling or oil refining comprises for example oil cuttings, oily soil, waste oil, spent activated carbon, solid oily waste or slop oils. The waste from oil drilling or oil refining may also comprise bio sludge from the water treatment of an oil drilling and/or oil converting plant.

[0016] According to an embodiment the fuel comprises tire waste, such as shredded used tires.

[0017] Preferably the waste originates from a plurality of sources. According to an embodiment the fuel comprises both refuse-derived fuel (RDF) and waste from oil drilling or oil refining. In other words the fuel comprises a mixture of RDF and waste from oil drilling or oil refining. Preferably the fuel consists of a mixture of RDF and waste from oil drilling or oil refining.

[0018] The disclosure also relates to a method of producing steam. The method comprises the step of providing fuel adapted to be combusted in a furnace or adapted to be gasified in a gasifier. According to an embodiment the step of providing fuel comprises providing waste that has been shredded, dehydrated and screened. According to an embodiment the step of providing fuel comprises steps of providing waste, shredding waste, dehydrating waste and screening waste.

[0019] The method also comprises the step of combusting fuel in a furnace for producing heat. For example the furnace is a fluidized bed furnace, such as atmospheric fluidized bed furnace, pressurized fluidized bed furnace, bubbling fluidized bed furnace or circulating fluidized bed furnace.

[0020] Alternatively the method comprises the step of gasifying fuel in a gasifier for producing combustible gas. For example the gasifier is a fluidized bed gasifier. In this case the method comprises the step of combusting combustible gas produced in the step of gasifying fuel in a gas burner for obtaining heat.

[0021] The method also comprises the step of producing steam using heat produced in the step of combusting fuel or in the step of combusting combustible gas.

[0022] The fuel comprises refuse-derived fuel (RDF) and waste from oil drilling or oil refining. In other words the fuel comprises a mixture of RDF and waste from oil drilling or oil refining. Preferably RDF is solid recovered fuel (SRF). For example the fuel comprises at least 25 % waste from oil drilling or oil refining. Preferably the fuel comprises at least 50 % solid recovered fuel (RDF) and waste from oil drilling or oil refining. More preferably the fuel comprises at least 75 % solid recovered fuel (RDF) and waste from oil drilling or oil refining. Most preferably the fuel comprises at least 90 % solid recovered fuel (RDF) and waste from oil drilling or oil refining. According to an embodiment the fuel consists of solid recovered fuel (RDF) and waste from oil drilling or oil refining. In other words the fuel consists of a mixture of RDF and waste from oil drilling or oil refining.

[0023] According to an embodiment the waste from oil drilling or oil refining comprises for example oil cuttings, oily soil, waste oil, spent activated carbon, solid oily waste or slop oils. The waste from oil drilling or oil refining may also comprise bio sludge from the water treatment of an oil drilling and/or oil converting plant.

Claims

1. A method for improving production of oil from an oil reservoir, wherein the method comprises the steps of
providing fuel comprising waste, the fuel being adapted to be combusted in a furnace; combusting fuel in a furnace for producing heat;
producing steam using heat produced in the step of combusting fuel; and
feeding steam produced in the step of producing steam to the oil reservoir.

2. A method for improving production of oil from an oil reservoir, wherein the method comprises the steps of
providing fuel comprising waste, the fuel being adapted to be gasified in a gasifier; gasifying fuel in a gasifier for producing combustible gas;
combusting combustible gas produced in the step of gasifying fuel in a gas burner for producing heat;
producing steam using heat produced in the step of combusting combustible gas; and feeding steam produced in the step of producing steam to the oil reservoir.

3. A method according to claim 1 or 2, wherein the fuel comprises at least 25 % waste, preferably at least 50 %, more preferably at least 75 %, and most preferably at least 90%.

4. A method according to any one of the preceding claims, wherein the fuel consists of waste.

5. A method according to any one of the preceding claims, wherein the step of providing fuel comprises steps of providing waste, shredding waste, dehydrating waste and screening waste.

6. A method according to any one of the preceding claims, wherein the waste has a positive calorific value.

7. A method according to any one of the preceding claims, wherein the fuel comprises refuse-derived fuel (RDF).

8. A method according to claim 6, wherein the fuel comprises at least 25 % RDF, preferably at least 50 %, more preferably at least 75 %, and most preferably at least 90%.

9. A method according to any one of the preceding claims, wherein the fuel comprises waste originating from oil drilling or oil refining.

10. A method according to claim 8, wherein the fuel comprises at least 25 % waste originating from oil drilling or oil refining, preferably at least 50 %, more preferably at least 75 %, and most preferably at least 90 %.

11. A method according to any one of the preceding claims, wherein the fuel comprises solid recovered fuel (RDF) and waste from oil drilling or oil refining.

12. Method of producing steam, wherein the method comprises the steps of providing fuel adapted to be combusted in a furnace;
combusting fuel in a furnace for producing heat; and
producing steam using heat produced in the step of combusting fuel;
characterized in that the fuel comprises refuse-derived fuel (RDF) and waste from oil drilling or oil refining.

13. Method of producing steam, wherein the method comprises the steps of providing fuel adapted to be gasified in a gasifier;
gasifying fuel in a gasifier for producing combustible gas;
combusting combustible gas produced in the step of gasifying fuel in a gas burner for producing heat;
producing steam using heat produced in the step of combusting combustible gas;
characterized in that the fuel comprises refuse-derived fuel (RDF) and waste from oil drilling or oil refining.