CN109973062A - An optimized five-three slug system - Google Patents

Abstract

The invention proposes an optimized five-three slug system, which belongs to the technical field of oilfield depth regulation and displacement engineering. The injection slug system adopts a combined structure of a multi-particle system and a gel system, and is suitable for deep profile control and oil displacement in oil fields. It has the characteristics of high incremental recovery.

Description

An optimized five-three slug system

technical field

The invention relates to an optimized oil field injection five-three slug process, and belongs to the technical field of oil field flooding engineering.

Background technique

At present, domestic oilfields basically use a single particle system (such as asphalt particles, polyacrylamide particles, emulsified particles CDG, etc.) or gel system (chromium ion PAM system, composite ion PAM system, etc.) or polymer system (PAM polymer system) , ternary composite system, etc.) for deep profile control flooding, but the single application of the above systems has the disadvantages of poor water blocking effect and low oil recovery efficiency.

SUMMARY OF THE INVENTION

In order to solve the defects of poor water blocking effect and poor oil recovery effect of single system depth profile control in the prior art, the present invention proposes a five-three slug injection system by using a square double-layer artificial core, and the adopted technical scheme is as follows:

An optimized five-three slug system for oil well injection, the volume of the injection slug system is a quarter of the pore volume of the upper high-permeability layer of the double-layer artificial square core (the simulated on-site control and displacement radius is the distance between the water well and the oil well 1/4 of the spacing between wells), the permeability of the double-layer artificial square core in the indoor model experiment: 100md/400md; the injection slug system includes five segments, and each of the five segments The segment body also includes three micro-segment bodies; the three micro-segment bodies are respectively: the combination of the gel liquid slug body, the suspended particle slug body and the water slug body, the volume ratio of the three micro-segment bodies is 1:1:1, and; the sum of the volumes of the three micro-segments is one-fifth of the total volume of the segments where they are located.

Further, the gel liquid slug body adopts the JLJ-2 composite crosslinking agent injection slug system; the suspended particle slug body adopts the sludge suspended particle system; and the water slug body adopts the simulated water. Wherein, the simulated water refers to the separated water from the oil field produced fluid (ie, the water separated from the oil-water mixture), and the simulated water conforms to the formation conditions.

Further, the concentration of suspended particles in the suspended particle slug body is 3.5%.

Further, the design of the injection slug system is as follows:

Step 1: According to the length of the double-layer artificial square core and the ratio of the radius of the injection slug to 1/4 of the well spacing and combined with the depth of the injection slug: V=[(end surface area÷2)×square core length×0.25]÷4, Obtain the total volume of the injection slug;

Step 2: Use the double-layer artificial square core displacement device to saturate the square core with simulated water;

Step 3: Using a double-layer artificial square core displacement device to saturate the square core with simulated oil;

Step 4: level the core holder of the double-layer artificial square core displacement device, use simulated water to displace the core column of the double-layer artificial square core, and connect a graduated pipette at the outlet of the core holder , and measure the ratio of oil to water in the produced fluid; when the water cut at the outlet reaches over 90%, water flooding is completed, and this is the best time to drive in the injection slug system;

Step 5: Add the gel injection slug system, the clay suspended particle injection slug system and the water slug body of the first segment body in the five segments to the pipeline of the double-layer artificial square core displacement device, and use The advection pump is driven into the core holder at a flow rate of 1ml/min, and stops after driving for 5 minutes and 3 seconds (five minutes and 3 seconds), during which the pressure change is recorded;

Step 6: After three days, repeat Step 5 until the fifth section is displaced. After three days, use an advection pump to simulate water-flooding of crude oil in the core at a flow rate of 1ml/min, until the outlet section of the core is free of oil. Record the total volume V ₂ of simulated oil driven out in steps 5 and 6, recovery factor increment=(V ₂ -V ₁ )÷V ₀ . The temperature of the above-mentioned water bath was all 40°C.

The preparations for the indoor physical model test are as follows:

Further, the square rock heterogeneous core displacement device comprises a manual pump 1, a manual pump 2 2, a square core holder 3, a measuring cup 4, a diaphragm container 5, a pipeline valve 6, a pipeline valve 2 7, a pipeline Valve three 8 and constant temperature box 9; the pump port end of the manual pump two 2 is connected with the side wall inlet end of the square core holder 3 through the pipeline; the bottom suction port of the square core holder 3 is set in In the cup body of the measuring cup 4; the top inlet of the square core holder 3 is connected to the inlet end of the diaphragm container 5 through a pipeline; the top inlet of the square core holder 3 is connected to the manual through a pipeline. The pump port end of pump one 1 is connected; the bottom port of the diaphragm container 5 is connected to the pump port end of the manual pump one 1 through a pipeline; the top inlet of the square core holder 3 is connected to the diaphragm container Pipeline valve one 6 is provided on the pipeline connecting the inlet end of 5; pipeline valve three 8 is provided on the pipeline connecting the top inlet of the square core holder 3 with the pump port end of the manual pump one 1; A pipeline valve 3 8 is provided on the pipeline connecting the bottom port of the diaphragm container 5 with the pump port end of the manual pump 1; the square core holder 3, the measuring cup 4, the diaphragm container 5, the pipeline valve 1 6, The second pipeline valve 7 and the third pipeline valve 8 are set in the constant temperature box 9 .

Further, the specific process of the square double-layer artificial core saturated with simulated water in step 2 is: at a temperature of 40°C, place the square core holder 3 vertically, and close the pipeline valve 1 6 and pipeline valve 2 7, Open the pipeline valve 3 8, use the manual pump 2 2 to provide a ring pressure of 2Mpa for the square core holder 3, and then use the manual pump 1 1 to provide a small amount of negative pressure for the square core holder 3, and slowly clamp the square core The air in the holder 3 is extracted, and the negative pressure formed inside the square core holder 3 slowly draws the simulated water in the measuring cup into the square core holder 3, so that the water in the square core holder 3 The square core is saturated with simulated water.

Further, the concrete process of the described square core saturated simulated oil in step 3 is: the simulated oil is loaded into the described diaphragm container 5, the pipeline valve one 6 and the pipeline valve two 7 are opened, the pipeline valve three 8 is closed, and the manual pump one is used. 1 Displace the simulated oil of the diaphragm container 5, so that the simulated oil slowly fills the core located in the square core holder 3 from top to bottom, and is driven to the outlet end of the square core holder 3 without water; The square core holder 3 after simulating water is placed in a constant temperature box at 40°C to ensure that the simulated oil has a certain fluidity. Time to observe whether there is an oil-water layer in the driving fluid. When the oil-water layer cannot be observed in the driving fluid, it is considered that the simulated oil is completely saturated, and the volume V ₀ of the driven simulated oil is recorded. The core can be used for the next water flooding experiment or injection slug experiment.

Further, the square-shaped double-layer artificial rock core saturated with simulated oil according to the above conditions is driven into the simulated water with a flow rate of 1ml/min by advection pump in the above-mentioned equipment until no oil is left, and the total water flooded out is recorded. Simulated oil volume V ₁

Further, the preparation process of the simulated oil described in step 3 is as follows:

Step 1: Heat the crude oil to 40°C for standby;

Step 2: According to the on-site crude oil viscosity data, add kerosene to the crude oil, and after mixing evenly, use a six-speed rotational viscometer to measure the simulated oil viscosity to be 7.8 mPa.s, that is, to obtain the required simulated oil;

Step 3: After the simulated oil is prepared, put it in an airtight container for later use.

Beneficial effects of the present invention:

The injection slug system proposed by the present invention increases the composite blocking effect of the injection slug by compounding various injection slug systems, avoids a single blocking effect, and increases the oil displacement efficiency; at the same time, through the design of the injection slug body structure and The design of the segment-to-body ratio effectively reduces the problem of weak blocking force of a single injection slug in the segment body, and achieves the optimum degree of water blocking force. Under this ratio, the resistance of the injection slug to water is just right, realizing the water flow The plugging effect is the best, and the recovery factor is the best. At the same time, the injection slug system proposed by the invention can increase the recovery factor to 17.5%.

Description of drawings

FIG. 1 is a schematic structural diagram of the square double-layer artificial core displacement device according to the present invention.

Fig. 2 is a schematic diagram of a square double-layer artificial core structure.

Detailed ways

The present invention will be further described below in conjunction with specific examples, but the present invention is not limited by the examples.

Example 1:

An optimized five-slug injection system, the volume of the injection slug system is one-third of the pore volume of the upper high-permeability layer of the double-layer artificial square core (the simulated on-site control and displacement radius is the distance between the water well and the oil well One-third well spacing), permeability: 100md/400md; the injection slug system includes five segments, and each of the five segments also includes three micro-segments; The three micro-segments are respectively: the combination of the gel liquid slug body, the suspended particle slug body and the water slug body, the volume ratio of the three micro-segments is 1:1:1, and; the three The sum of the volumes of the micro-segments is one-fifth of the total volume of the injected segments. The double-layer artificial square rock core adopts a rectangular cube structure, and it includes two parts, the upper layer and the lower layer, wherein the length of the double-layer artificial square rock core is 30.3cm; the rectangular end face size of the double-layer artificial square rock core is 4.5cm ×4.5cm, the thickness of the upper layer and the lower layer are the same.

The gel liquid slug body adopts JLJ-2 cross-linking agent injection slug system; the suspended particle slug body adopts sludge suspended particle system; the water slug body adopts simulated water. The suspended particle concentration in the suspended particle slug body is 3.5%.

The gel liquid slug body adopts JLJ-2 conforming to the cross-linking agent injection slug system; the water slug body adopts simulated water. Wherein, the simulated water refers to the separated water from the oil field produced fluid (ie, the water separated from the oil-water mixture), and the simulated water conforms to the formation conditions.

The design of the injection slug system is as follows:

Step 1: According to the length of the double-layer artificial square core and the ratio of the radius of the injection slug to 1/4 of the well spacing and combined with the depth of the injection slug: V=[(end surface area÷2)×square core length×0.25]÷4, Obtain the volume V of the injection slug;

Step 2: using a double-layer artificial square core displacement device to saturate the square core with simulated water;

Step 3: Using a double-layer artificial square core displacement device to saturate the square core with simulated oil;

Step 4: Flatten the core holder of the double-layer artificial square core displacement device, replace the core column of the double-layer artificial square core with simulated water, and connect a graduated pipette at the outlet of the core holder , and measure the oil-water ratio in the produced fluid; when the water content at the outlet end reaches more than 90%, the water flooding is completed, and this is the best time for the injection slug system to drive in;

Step 5: Add the gel injection slug system, the clay suspended particle injection slug system and the water slug body of the first segment body in the five segments to the pipeline of the double-layer artificial square core displacement device, and use The advection pump is driven into the core holder at a flow rate of 1ml/min, and stops after driving for 5 minutes and 3 seconds (five minutes and 3 seconds), during which the pressure change is recorded;

Step 6: After three days, repeat Step 5 until the fifth section is displaced. After three days, use an advection pump to simulate water-flooding of crude oil in the core at a flow rate of 1ml/min, until the outlet section of the core is free of oil. Record the total volume V ₂ of the simulated oil driven out in steps 4 to 6, recovery factor increment=(V ₂ -V ₁ )÷V ₀ ×100%.

The specific process of saturating the simulated water for the square double-layer artificial core in the second step is as follows: at a temperature of 40° C., place the square core holder 3 vertically, close the pipeline valve 1 6 and the pipeline valve 2 7, and open the pipeline valve 38. Use hand pump 2 2 to provide a ring pressure of 2Mpa for the square core holder 3, and then use hand pump 1 1 to provide a small amount of negative pressure for the square core holder 3, and slowly move the square core holder 3 The air in the square core holder 3 is drawn out, and the negative pressure formed inside the square core holder 3 slowly draws the simulated water in the measuring cup into the square core holder 3, so that the square core in the square core holder 3 is saturated Simulate water.

The specific process of the square rock core saturation simulated oil described in step 3 is: put the simulated oil into the diaphragm container 5, open the pipeline valve 1 6 and the pipeline valve 2 7, close the pipeline valve 3 8, and use the manual pump 1 to displace The simulated oil in the diaphragm container 5 makes the simulated oil slowly fill the rock core located in the square core holder 3 from top to bottom, and drives to the outlet end of the square core holder 3 without water; The square core holder 3 is placed in a constant temperature box at 40°C to ensure that the simulated oil has a certain fluidity, and the simulated oil is displaced by the simulated water under a pressure of 0.2MPa, and the simulated water is observed every five minutes Whether there is oil-water layer in the displacing liquid, if the oil-water layer cannot be observed in the displacing liquid, it is considered that the simulated oil is completely saturated, and the volume V ₀ of the simulated oil driven in is recorded. The core can be used for the next water flooding experiment or slug injection experiment.

The square double-layer artificial core that has been saturated with simulated oil according to the above conditions is driven into the simulated water at a flow rate of 1 ml/min with an advection pump in the above-mentioned equipment, and the simulated oil is driven out by recording the total amount of water driven out. Volume V ₁

The preparation process of the simulated oil described in step 3 is as follows:

Step 1: Heat the crude oil to 40°C for use;

Step 2: According to the crude oil viscosity data on site, add kerosene to the crude oil, mix evenly, measure the simulated oil viscosity with a six-speed rotary viscometer to be 7.8mPa.s, and obtain the required simulated oil;

Step 3: After the simulated oil is prepared, put it in an airtight container for later use.

The square rock heterogeneous core displacement device comprises a manual pump 1, a manual pump 2 2, a square core holder 3, a measuring cup 4, a diaphragm container 5, a pipeline valve 1 6, a pipeline valve 2 7, and a pipeline valve 3 8 and the constant temperature box 9; the pump port end of the manual pump 2 is connected with the side wall inlet end of the square core holder 3 through a pipeline; the bottom suction port of the square core holder 3 is arranged in the measuring cup 4; the top inlet of the square core holder 3 is connected to the inlet end of the diaphragm container 5 through a pipeline; the top inlet of the square core holder 3 is connected to the manual pump through a pipeline 1 The bottom port of the diaphragm container 5 is connected to the pump port end of the manual pump 1 through a pipeline; the top inlet of the square core holder 3 is connected to the inlet of the diaphragm container 5 Pipeline valve one 6 is provided on the pipeline connected at the ends; pipeline valve three 8 is provided on the pipeline connecting the top inlet of the square core holder 3 with the pump port end of the manual pump one 1; A pipeline valve 3 8 is provided on the pipeline connecting the bottom port of the container 5 with the pump port end of the manual pump 1; the square core holder 3, the measuring cup 4, the diaphragm container 5, the pipeline valve 1 6, the pipeline valve 2 7. The pipeline valves 3 8 are all set in the constant temperature box 9 .

Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Any person familiar with this technology can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore The scope of protection of the present invention should be defined by the claims.

Claims (9)

1. a kind of five or the three slug system of oil well note of optimization, which is characterized in that the volume of the slug system is the double-deck artificial side The one third volume of shape rock core top high permeability zone pore volume；The artificial rectangular core permeability of bilayer: 100md/ 400md；The note slug system includes five segment bodies, and each segment body further includes three micro- segment bodies in five segment bodies； Three micro- segment bodies are respectively as follows: coagulant liquid slug body, suspended particulate slug body and water slug body and combine, and described three micro- section The volume ratio of body is 1:1:1, and；The sum of volume of three micro- segment bodies is 1/5th of segment body total volume where it.

2. slug system according to claim 1, which is characterized in that the coagulant liquid slug body uses JLJ-2 composite crosslinking Slug system is infused in agent；The suspended particulate slug body uses sludge suspension granular system；The water slug body is using simulation water.

3. slug system according to claim 2, which is characterized in that concentration of suspended particles is in the suspended particulate slug body 3.5%.

4. slug system according to claim 1, which is characterized in that the coagulant liquid slug body meets crosslinking using JLJ-2 Slug system is infused in agent；The water slug body is using simulation water.

5. slug system according to claim 1, which is characterized in that experimental temperature is 40 DEG C in object mould insulating box, the note The design of slug system is as follows:

Step 1: according to the ratio of 1/4 well spacing shared by the double-deck artificial rectangular rock core length and note slug radius and note section is combined Fill in depth model: V=[(face area ÷ 2) × rectangular rock core length × 0.25] ÷, 4, obtain note slug total volume；

Step 2: make rectangular rock core saturation simulation water using the double-deck artificial rectangular rock core displacement device；

Step 3: make rectangular rock core saturation simulation oil using the double-deck artificial rectangular rock core displacement device；

Step 4: being laid flat the core holding unit of the double-deck artificial rectangular rock core displacement device, with simulation water drive for double-deck artificial rectangular The core column of rock core in the graduated pipette of outlet port of rock core holder tape splicing, and measures oil-water ratio in Produced Liquid； Water drive is completed when outlet end moisture content is to 90% or more, the best opportunity driven at this time for note slug system；

Step 5: the gel note slug system of first segment body in five segment bodies, clay suspended particulate are infused into slug body The pipeline of the double-deck artificial rectangular rock core displacement device is added in system and water slug body, and is driven with constant-flux pump with the flow velocity of 1ml/min Enter in core holding unit, drives 5min 3s (3 seconds five minutes) and stop afterwards, during which record pressure change；

Step 6: after three days, repeating step 5, until the displacement of the 5th segment body is completed, after three days, with constant-flux pump with 1ml/ The flow velocity of min carries out simulation water drive rock core Crude Oil, and displacement is oil-free to rock core outlet section, and recording step five and step 6 displace mould Quasi- oil total volume V₂, recovery ratio increment=(V₂-V₁)÷V₀× 100%.Above-mentioned bath temperature is all 40 DEG C.

6. slug system according to claim 5, which is characterized in that the rectangular artificial core driving device includes manual pump One (1), manual pump two (2), rectangular core holding unit (3), measuring cup (4), membrane vessel (5), pipeline valve one (6), line valve Two (7) of door, pipeline valve three (8) and insulating box (9)；The pumping hole end of the manual pump two (2) passes through pipeline and the rectangular rock The side wall entrance end of heart clamp holder (3) is connected；The bottom end suction inlet of the rectangular core holding unit (3) is set to the measuring cup (4) Cup body in；The top inlet of the rectangular core holding unit (3) passes through the arrival end phase of pipeline and the membrane vessel (5) Even；The top inlet of the rectangular core holding unit (3) is connected by pipeline with the pumping hole end of the manual pump one (1)；It is described Membrane vessel (5) bottom nozzle is connected by pipeline with the pumping hole end of the manual pump one (1)；In the rectangular core holding unit (3) pipeline that top inlet is connected with the arrival end of the membrane vessel (5) is equipped with pipeline valve one (6)；In the side The pipeline that the top inlet of shape core holding unit (3) is connected with the pumping hole end of the manual pump one (1) is equipped with pipeline valve three (8)；Pipeline valve is equipped on the pipeline that the membrane vessel (5) bottom nozzle is connected with the pumping hole end of the manual pump one (1) Three (8)；The rectangular core holding unit (3), measuring cup (4), membrane vessel (5), pipeline valve one (6), pipeline valve two (7), Pipeline valve three (8) is set in insulating box (9).

7. slug system according to claim 7, which is characterized in that rectangular rock core saturation simulation water is specific described in step 2 Process are as follows: 50 DEG C at a temperature of, rectangular core holding unit (3) is placed vertically, and closes pipeline valve one (6) and line valve Two (7) of door, are opened pipeline valve three (8), are that rectangular core holding unit (3) provide the ring pressure of 2Mpa, then use with manual pump two (2) Manual pump one (1) is that rectangular core holding unit (3) provide negative pressure, slowly extracts the air in rectangular core holding unit (3) out, The negative pressure formed inside the rectangular core holding unit (3) by the simulation water in measuring cup slowly be pumped into rectangular core holding unit (3) in, make the rectangular rock core saturation simulation water in rectangular core holding unit (3).

8. slug system according to claim 7, which is characterized in that rectangular rock core saturation simulation oil is specific described in step 3 Process are as follows: simulation oil is fitted into the membrane vessel (5), opens pipeline valve one (6) and pipeline valve two (7), closes pipe Line valve three (8), the simulation oil of membrane vessel (5), fills simulation oil slowly from top to bottom described in manual pump one (1) displacement The rock core being completely located in rectangular core holding unit (3), the outlet end for being driven to rectangular core holding unit (3) are anhydrous；By saturation simulation Rectangular core holding unit (3) after water is placed in 40 DEG C of insulating box, to guarantee that simulation oil has certain mobility, in 0.2MPa Pressure under carry out the displacement simulation water of simulation oil, and displace liquid with container mobile phone, and each 5 minutes primary its of observation are displaced Whether liquid has grease layering, and observes Flooding Efficiency, when grease layering can not be observed by displacing liquid, then assert simulation Oil is fully saturated, and records and drive in simulation oil volume V₀.The artificial rectangular rock core of simulation oil will be saturated by above-mentioned condition, In above equipment, simulation water is driven in the flow velocity of 1ml/min with constant-flux pump, be driven to it is oil-free, record displace total water drive go out simulate Oil volume V₁。

9. slug system according to claim 7, which is characterized in that the preparation process of simulation oil described in step 3 is as follows:

Step 1: heating crude oil is spare to 40 DEG C；

Step 2: kerosene is added in Xiang Suoshu crude oil according to live viscosity of crude data, after mixing with six fast rotary viscosities Meter measurement simulation oil viscosity be 7.8mPa.s to get arrive required simulation oil；

Step 3: being put into spare in closed container after simulation oil is prepared.