METHOD FOR FORMING A GAS PHASE IN WATER SATURATED HYDROCARBON RESERVOIRS
The present disclosure describes a method of recovering oil and gas from a hydrocarbon-containing reservoir generally having some degree of water saturation within the reservoir pore network by injecting a gas into the reservoir. The method applicable to reservoirs having high water saturation of about 50 percent or greater. High water saturation in a reservoir can cause excessive amounts of water to be produced to produce the hydrocarbons. Coproduction and management of this water is costly and burdensome to operations leaving many reservoirs of oil and gas are stranded, rendering the production uneconomic. The method described herein addresses this need and other needs. The injection gas (with or without other hydrocarbons) can coalesce with the hydrocarbons contained within the hydrocarbon-containing reservoir to form a continuous phase of hydrocarbons within the reservoir. Once the targeted volume of the injection gas is injected, the flow is reversed producing the gathered hydrocarbons.
1 . A method, comprising:
providing a gas;
injecting the provided gas into a hydrocarbon-containing reservoir having a first water-to-gas production ratio, wherein the hydrocarbon-containing reservoir comprises a gaseous hydrocarbon, wherein the provided gas is injected at rate of from about 10 mcfd or more to about no more than about 8,000 mcfd;
ceasing the injection of the provided gas; and
gathering from the hydrocarbon-containing reservoir a gathered-gas mixture comprising the provided gas and some of the gaseous hydrocarbons from the hydrocarbon-containing reservoir, wherein the hydrocarbon-containing reservoir producing the gathered-gas mixture has a second water-to-gas production ratio and wherein the second water-to-gas ratio is no more than the first water-to-gas ratio.
2 . The method of claim 1 , wherein the provided gas injected into the hydrocarbon-containing reservoir is selected from the group consisting essentially of methane, ethane, propane, nitrogen, butane, air, oxygen, argon, carbon dioxide, helium or mixture thereof.
3 . The method of claim 1 , wherein, prior to the injecting of the provided gas, the hydrocarbon-containing reservoir comprises a plurality of discrete hydrocarbon phases, wherein the plurality of discrete hydrocarbon phases is in the form of one or more pockets and bubbles of hydrocarbons, wherein the injecting of the provided gas coalesces the one or more of the plurality of discrete hydrocarbon phases into one or more continuous hydrocarbon phases.
4 . The method of claim 1 , wherein the gather gas mixture comprises the provided gas and the gaseous hydrocarbons having from about 2 to about 98 volume % the provided gas and from about 98 to about 2 volume % the gaseous hydrocarbon.
5 . The method of claim 1 , wherein the gaseous hydrocarbon comprises one of methane, ethane, propane, n-butane, isobutane, ethylene, propylene, 1-butene, and mixture thereof.
6 . The method of claim 1 , wherein the first water to gaseous hydrocarbon is from about 1 bbl water/1000 MCF to about 2000 bbl water/1000 MCF.
7 . The method of claim 1 , wherein the second water to gaseous hydrocarbon ratio is from about 98% to about 2% of first water to gaseous hydrocarbon ratio.
8 . The method of claim 1 , wherein the injecting of the provided gas is for a period from about five days to about three months.
9 . The method of claim 1 , wherein the gaseous hydrocarbon gas comprises methane.
10 . A method, comprising:
providing a well having first water to gas production ratio;
providing a gas;
injecting the provided gas into a well bore, wherein the wellbore traverses a hydrocarbon-containing reservoir, wherein the hydrocarbon-containing reservoir comprises a gaseous hydrocarbon;
ceasing the injection of the provided gas; and
producing from the wellbore a mixture of the provided gas and some of the gaseous hydrocarbons having a second water to gas production ratio, wherein the first water-to-gas ratio is greater than the second water-to-gas ratio.
11 . The method of claim 10 , wherein the hydrocarbon-containing reservoir comprises pore volumes having a porosity and permeability, and wherein, prior to the injecting of the provided gas, the hydrocarbon-containing reservoir comprises a plurality of discrete hydrocarbon phases contained within the pore volumes and wherein the injecting of the provided gas coalesces the one or more of the plurality of discrete hydrocarbon phases into one or more continuous hydrocarbon phases, and wherein the one or more continuous hydrocarbon phases span three or more pore volumes.
12 . The method of claim 11 , wherein the gaseous hydrocarbon comprises one of methane, ethane, propane, n-butane, isobutane, ethylene, propylene, 1-butene, and mixture thereof.
13 . The method of claim 10 , wherein the first water to gaseous hydrocarbon is from about 1 bbl water/1000 MCF to about 2000 bbl water/1000 MCF.
14 . The method of claim 10 , wherein the provided gas injected into the hydrocarbon-containing reservoir is one of methane, ethane, propane, nitrogen, butane, air, oxygen, argon, carbon dioxide, helium or mixture thereof.
15 . The method of claim 10 , wherein the injecting of the provided gas into the wellbore is at a pressure below the fracture press of the hydrocarbon-containing reservoir.
16 . The method of claim 10 , wherein the second water to gaseous hydrocarbon ratio is from about 98% to about 2% of first water to gaseous hydrocarbon ratio.
17 . The method of claim 10 , wherein the mixture of the provided gas and some of the gaseous hydrocarbons comprises from about 2 to about 98 volume % the provided gas and from about 98 to about 2 volume % the gaseous hydrocarbon.
18 . The method of claim 10 , wherein the injecting of the provided gas is for a period from about five days to about three months.
19 . A method, comprising:
providing a target well having a first water to gas production ratio from about 1 bbl water/1000 MCF to about 2000 bbl water/1000 MCF;
providing a gas;
injecting the provided gas into a well bore, wherein the wellbore traverses the hydrocarbon-containing reservoir, wherein the provided gas is injected at a rate of from about 10 mcfd or more to about no more than about 8,000 mcfd; and
producing, after the ceasing of the injection of the provided gas, from the target well at a second water to gaseous hydrocarbon ration, wherein the second water to gaseous hydrocarbon ratio is from about 98% to about 2% of first water to gas production ratio.
20 . The method of claim 19 , wherein the provided gas injected into the hydrocarbon-containing reservoir is one of methane, ethane, propane, nitrogen, butane, air, oxygen, argon, carbon dioxide, helium or mixture thereof and wherein the injecting of the provided gas into the wellbore is at a pressure below the fracture press of the hydrocarbon-containing reservoir.