CN101126312B

CN101126312B - Fluctuation petroleum exploitation method

Info

Publication number: CN101126312B
Application number: CN 200710052981
Authority: CN
Inventors: 魏宁; 李小春
Original assignee: Wuhan Institute of Rock and Soil Mechanics of CAS
Current assignee: Wuhan Institute of Rock and Soil Mechanics of CAS
Priority date: 2007-08-17
Filing date: 2007-08-17
Publication date: 2013-01-23
Anticipated expiration: 2027-08-17
Also published as: CN101126312A

Abstract

The invention discloses a fluctuation oil production method, which relates to an oil production method. The invention comprises that: (1) an injectant containing air is formed and the injectant is injected into a manto (3) through an injection well (2) or a recovery well (1); (2) the pressure of the injection well (2) and the recovery well is kept (1) for a period of time so that the oil and the injectant are mixed into more uniform fluid;(3) the pressure of the injection well (2) and the recovery well (1) is decreased, the pressure of the manto(3) is decreased and the oil-containing mixed fluid is obtained from the recovery well (1) or the injection well (2); (4) the procedure of (1), (2) and (3) is repeated, the pressure fluctuation of the fluid in the manto (3) is realized until the oilrecovery rate is less than the economic recovery rate. The invention is suitable for the oil production field and can be suitable for any manto so long as the displacement exploitation is possible; a lso the invention can be suitable for the manto that is unsuitable for the displacement exploitation due to the strong heterogeneity of the manto, which greatly breaks through the scope and recovery rate of the traditionally displacement exploitation method.

Description

Fluctuation petroleum exploitation method

Technical field

The present invention relates to a kind of petroleum exploitation method, relate in particular to a kind of petroleum exploitation method based on gas-liquid mixed characteristic and pressure oscillation.

Background technology

The technology such as the primary recovery of traditional petroleum driving mining, secondary recovery, tertiary recovery; Its exploitation method mainly contains extraction, water drive, gas drive, aqueous vapor and replaces the methods such as displacement, underground combustion, water vapour, polymer flooding, reduces oil content viscosity, increases the oil content flowing velocity.But they all face, and limit of mining is limited, advantage flows in the recovery process, the advantages such as fingering, displacement dead angle flow and the Non-Uniform Flow phenomenon, and the recovery ratio of oil and the speed of gathering can only reach certain degree.The scope and the recovery ratio that how to improve oil exploitation become an important indicator weighing the oilfield exploitation situation.The relative position of Injection Well and producing well directly has influence on limit of mining and the recovery ratio of leachant; Rock And Soil has directly reduced the recovery ratio of mineral reserve for strongly non-homogeneous, the material (crack, solution cavity, molten chamber, non-homogeneous sandstone, change infiltration initial hydraulic gradient, fluid degree of becoming sticky, the variation of three-phase relative coefficient of permeability etc.) of the high coefficient of variation, the nonuniformity of oil content viscosity have formed various low district or exploitation dead band of gathering simultaneously.

In sum, traditional oil exploitation has following shortcoming:

1. the mining effect scope is affected by the relative position of Injection Well and producing well, and the impact that recovering range and the intensity of gathering can be subject to holing and arrange has gather dead angle and the dead band of gathering.

2. because the non-linear nature of the heterogeneity of the character of ore bed rock soil medium and fluid and oil content causes low mining area and exploitation dead band (as shown in Figure 1, 2), and recovery process is limited on the impact of ore bed, form low recovery ratio.

3. advantage mobile (as shown in Figure 1, 2) can appear in oil reservoir in recovery process, and along with the process of exploitation, advantage flows and can aggravate, the recovery ratio of reduction oil gas.Therefore, be necessary the phenomenon that the solution advantage flows.

How to improve limit of mining? how to solve because the molten difficulty of soaking that the variability of ore bed and fluid causes? how to improve recovery ratio and the recovering range of exploitation? these all are to need key problems-solving.

Summary of the invention

Purpose of the present invention just is to overcome the above-mentioned shortcoming and defect that prior art exists, and enlarges the scope of application of prior art, and a kind of fluctuation petroleum exploitation method is provided.The present invention is a kind of simple, effectively, and the method that can finish simultaneously with the conventional oil exploitation.

The object of the present invention is achieved like this.

Oil exploitation technology has become a kind of widely used oil exploitation method through the development in century more than one; Various exploitation methods have been widely used in the fields such as oil exploitation, for the proposition of fluctuation petroleum exploitation method is laid a good foundation.

Such as Fig. 3, the present invention includes the following step:

1. form the injectant of air inclusion, injectant is injected ore bed (3) by Injection Well (2) or producing well (1);

2. the pressure a period of time that keeps Injection Well (2) and producing well (1), oil content and injectant are mixed form more uniform fluid;

3. then reduce the pressure of Injection Well (2) and producing well (1), reduce ore bed (3) pressure, and obtain the oil-containing fluid-mixing at producing well (1) or Injection Well (2);

4. constantly 1. 2. 3. repeating step realizes the pressure oscillation of fluid in the ore bed (3), until the recovery ratio of oil is lower than the economic exploitation rate.

Operating principle of the present invention:

Form mixing (or miscible) fluid of gas and other additive (as: water, blowing agent, surfactant etc.) under the certain pressure, form injectant.Adopt the high pressure injection device that injectant is injected ore bed (3) by Injection Well (1); Keep ore bed (3) fluid pressure a period of time (time length is decided by concrete ore bed situation, and the time was from 1 minute to 3 years scope); Non-advantage flow surface and hypotonic zone (4) molecular diffusion and the disperse of injectant in ore bed, the fluid-mixing of formation injectant and oil.Because the existence of gas is so that fluid-mixing has the high compression swelling properties, then reduce the pressure of Injection Well (1) or producing well (2), cause the expansion of the fluid-mixing of ore bed (3), the oil of non-advantage flow region and hypotonic zone (4) taken out of the advantage of entering flows and height oozes zone (5), at Injection Well (1) or producing well (2) is arbitrary or both obtain petroliferous fluid recovered.

The present invention has following advantages and good effect:

1. reduce Injection Well (1) and producing well (2) well spacing position to the impact of recovery ratio and recovering range; Reduce the exploitation dead angle.

2. weaken because ore bed Nonuniform Domain Simulation of Reservoir (height oozes, crack, cave, fingering are serious etc.) causes the advantage of fluid to flow, increase injectant in flowing velocity, flow mechanism meeting and the time of hypotonic zone (4) and non-advantage flow region (7); The advantage that blends step-down flow the perimeter zone take molecular diffusion as main solute migration process as convection current and disperse as main transition process, accelerate whole displacement recovery process, weaken the advantage flow phenomenon to the negative effect of exploitation.

3. always face oil content non linear fluid flow through porous medium phenomenon in the oil exploitation process, form relatively exploitation dead band; In ore bed pressure oscillation process, form very high barometric gradient in hypotonic zone (4) and the mobile intra-zone of non-advantage, the oil content that relatively is in " exploitation dead band " can be flowed, participated in recovery process, improved recovering range and the recovery ratio of oil exploitation.

The present invention is applicable to field of petroleum exploitation, is applicable to any ore bed that can carry out the displacement exploitation; Also be applicable to owing to the ore bed heterogeneity is not suitable for carrying out the ore bed that displacement is exploited strongly scope and the recovery ratio of large quantum jump tradition displacement exploitation method.

Description of drawings

Fig. 1 is the oil content flow schematic diagram in advantage flow surface situation;

Fig. 2 is the oil content flow schematic diagram in hypotonic regional situation;

Fig. 3 is conventional exploitation sub-surface schematic diagram;

Fig. 4 is the flow process schematic diagram of the ore bed fluid of the present invention in the process of boosting;

Fig. 5 is the flow process schematic diagram of the ore bed fluid of the present invention in the step-down process;

Fig. 6 be the present invention liter, the flow process schematic diagram of ore bed fluid in the pressure drop pressure process.

Wherein:

The 1-producing well; The 2-Injection Well; The 3-ore bed;

The hypotonic zone of 4-; The high zone of oozing of 5-; The 6-fissure-plane;

7-exploits the dead band; The molten chamber of 8-or solution cavity.

The specific embodiment

The present invention is further described below in conjunction with drawings and Examples:

This method is to the innovation of conventional oil exploitation method and expansion, and some technology in the conventional method stand good in the present invention.

1, about the preparation engineering

By some existing treatment measures (as: methods such as vacuum method, aeration, gas displacement) the part moisture in the ore bed (3) is discharged formation unsaturation rock mass (not being liquid entirely in the rock mass hole), reserve certain space, enter hypotonic zone in order to comprise the high compression fluid-mixing of leachant.

2, about step 1.

Mix the injectant that forms air inclusion by liquid gas mixed method (such as spray-on process, bubble method etc.) or gas, form the fluid-mixing of high-compressibility; Gas componant is the gas (as: gases such as nitrogen, carbon dioxide, hydrogen, methane, ammonia, oxygen that do not produce violent chemical reaction under the controlled condition with oil content, it perhaps is the mixture of different proportion gas, such as air, flue gas, tail gas, waste gas), the volume of gas is in 0.01～100 times of scope of injectant volume; Different ratios can obtain different constrictive fluid-mixings;

Comprise certain moisture and the additives such as blowing agent, surfactant in the injectant, be convenient to injectant and mix (miscible) with oil content in the ore bed, form the high-compressibility fluid.3. can realize in forming the expansion of fluid-mixing aerated fluid or gas and oil and replace the shape fluid in step, gas or oil content do not form non-individual body.

Also can add some measures in the conventional oil exploitation method: heating, steam, burning, CO ₂, high molecular polymer reduces oil content viscosity, increase the flowing property of mixture.

By high pressure injection device (such as pump, forcing press, high-pressure bottle etc.) gas-liquid mixture fluid (air inclusion) of high-compressibility is injected ore bed (3) through Injection Well (1), and improve the pressure of fluid in the ore bed (3).

3, about step 2.:

The pressure a period of time that keeps Injection Well (2) and producing well (1), the time interval be 1 minute to 5 years, its main purpose be allow injectant flow or static process in ore bed in oil content in ore bed (3), fully mix formation high-compressibility fluid by molecular diffusion, convection current and dispersion.The both economical time interval is between 2 days to 3 months.

4, about step 3.

The step-down scope is as the criterion not destroy the ore bed rock mass, according to the injection pressure scope, reduces the amplitude of pressure in 0.1MPa～100MPa scope, and the decompression amplitude depends on the factors such as the geostatic stress, oil pressure, ore bed mechanical strength, fluid-mixing degrees of expansion of concrete ore bed.

In Injection Well (1) or producing well (2), collect the leaching solution that contains mineral reserve; Specific implementation method is for generally obtaining the method for underground fluid, and form is varied, for example: can adopt at Injection Well (1) and producing well (2) and utilize high-pressure pump to extract the ore bed fluid; Also can adopt fluid in the fluid displacement such as the injectant displacement ore bed to obtain to contain after the fluctuation exploitation ore bed fluid of mineral; Also can by discharging the pressure of Injection Well and producing well, utilize the high-compressibility (high-expansion) of ore bed fluid automatically to flow out.

Generally speaking, guarantee that the average pressure of Injection Well (1) is higher than the average fluid pressure of producing well (2), can guarantee that like this fluid in the limit of mining has the trend that flows from Injection Well (1) to producing well (2) all the time in the ore bed, avoid pressure oscillation to form middle exploitation blank tape.

5, about step 4.

Constantly repeat 1. 2. 3. to realize following purpose in the step process.

* in the injection process of boosting, miscible (mixing) fluid contraction is oozed zone (5) by height and is flowed into hypotonic zone (4), as shown in Figure 4.

* in the step-down process, fluid expands in hypotonic zone (4), and flows out hypotonic zone (4), enters height and oozes zone (5), as shown in Figure 5.

* form the high pressure gradients zone in hypotonic zone and non-advantage flow region, weaken the non-linear mobile phenomenon of oil content and the exploitation of high viscosity oil content, increase limit of mining and dynamics.

* in the situation that the fluid-flow mode of the flow surface that has superiority (passage) as shown in Figure 6, the constantly back and forth exchange between the exploitation dead band (7) of non-advantage flow region and the fissure-plane (6) of advantage flow surface or passage, molten chamber or the solution cavity (8) of miscible (mixing) fluid has changed the limitation that conventional method injectant (or displacement fluid) can not arrive non-advantage flow region.

Claims

1. a fluctuation petroleum exploitation method is characterized in that comprising the following steps:

The gas of described injectant is the gas that does not produce violent chemical reaction under the controlled condition with oil content;

Comprise certain moisture, blowing agent and surfactant additive in the injectant, be convenient to that injectant mixes with oil content in the ore bed or miscible, form the high-compressibility fluid;

The described time interval is 1 minute to 5 years;

The step-down scope is as the criterion not destroy the ore bed rock mass, according to the injection pressure scope, reduces the amplitude of pressure in 0.1MPa～100MPa scope;

4. constantly 1. 2. 3. repeating step realizes the pressure oscillation of fluid in the ore bed (3), until the recovery ratio of oil is lower than the economic exploitation rate;

In the injection process of boosting, miscible or fluid-mixing shrinks, and oozes zone (5) by height and flows into hypotonic zone (4);

In the step-down process, fluid expands in hypotonic zone (4), and flows out hypotonic zone (4), enters height and oozes zone (5);

Flow surface or passage in the situation that have superiority, miscible or constantly back and forth exchange between the exploitation dead band (7) of non-advantage flow region and the fissure-plane (6) of advantage flow surface or passage, molten chamber or solution cavity (8) of fluid-mixing.