WO2017000622A1

WO2017000622A1 - Storage-type precise quantitative injection system for injection of underground oil or gas well operating agent and injection method thereof

Info

Publication number: WO2017000622A1
Application number: PCT/CN2016/078947
Authority: WO
Inventors: 裴柏林; 吴建昌; 冯国江
Original assignee: 安东柏林石油科技（北京）有限公司
Priority date: 2015-06-30
Filing date: 2016-04-11
Publication date: 2017-01-05
Also published as: CN104948134B; CN104948134A

Abstract

A storage-type precise quantitative injection system for injection of an underground oil or gas well operating agent and an injection method thereof. The injection system comprises an injection tube (3-2) and overground pressurizing equipment. The injection tube is provided with one or more sets of injection units therein. Each set of the injection units comprises an operating agent container (3-7) having a variable volume. The overground pressurizing equipment is configured to generate a pressure acting on the operating agent container (3-7) having the variable volume so as to expel an operating agent (3-8). The injection method adopts the storage-type precise quantitative injection system using the underground oil or gas well operating agent (3-8), and injects a fixed amount of the operating agent (3-8) into a target location in the underground well. By injecting in advance the fixed amount of the operating agent into the operating agent container, the injection system can inject an accurate and fixed amount of the operating agent and ensure accuracy of an injection amount of the operating agent. The injection method can inject an accurate amount of the operating agent into the target location, providing accuracy of the injection amount and accuracy of the injection location and ensuring a favorable injection effect.

Description

Storage precision quantitative oil and gas well underground working agent injection system and injection method

Technical field

The invention relates to a storage precision quantitative oil and gas well working agent injection system and an injection method using the same, and belongs to the field of oil and natural gas exploitation. Oil and gas wells here refer to generalized oil and gas wells in oil and gas field development, including oil wells, gas wells, natural gas wells, injection wells, water injection wells, steam injection thermal recovery wells, steam stimulation wells, steam injection wells, deep wells and ultra-deep wells, horizontal wells, High-angle wells, directional wells, straight wells, etc.

Background technique

In the development of oil and gas fields, it is necessary to inject working agents into the well to improve the production conditions in the underground. The working agents injected downhole include the following categories:

(1) Plugging agents, including glue, cement, and infiltration agents;

(2) formation sand consolidation agent;

(3) valuable working agent, including detergent and plugging agent;

(4) A limited amount of working agent, such as an oxidizing agent, is required;

At present, the above-mentioned working agent is injected into the oil and gas well, and the oil field is directly injected into the oil and gas well from the ground through the ground injection equipment (such as a pump truck). Taking the injection molding of the well as an example, the injection method adopts two parts of the injection pipe and the packer disposed at both ends of the injection port to form a glue injection pipe column, and the upper part connects the work pipe column to the ground, and the glue is injected into the well through the ground equipment, and the colloid passes through. The working pipe column of the upper kilometer, through the closed annulus formed by the packer and the injection pipe, injects the glue into the outer ring of the production pipe and the target position of the formation; the packer adopts the expansion packer to block the space. Note both ends of the entrance. First, the pressure fluid is injected to expand the expansion packer, and the pressure in the tube is controlled by the constant pressure valve to make the pressure reach or exceed the setting pressure of the packer; therefore, the downhole injection system includes the injection tube and the isolation system. . The containment system includes a packer, and the expander packer is required to be equipped with a constant pressure valve and a retractable drain that can expand the packer.

This method of injection molding is described in detail in the Chinese invention patent “Completion Structure and Method for Establishing Separation in the Filling Ring of Oil and Gas Well Filters (Application No. 201410013598.8)”. This method is to fill the ring. The target layer is injected with a choke medium to form a choke ring. This choke ring is a packing section where the fluid is difficult to penetrate or even impermeable. The patent also proposes a method of placing a packer at both ends of the injection layer and then passing the injection string and setting A flow-through medium is injected into the fill ring at the injection port on the string.

As shown in Figure 1, in Figure 1: 1-1 is the ground injection equipment; 1-2 is the wellhead; 1-3 is the ordinary filter column; 1-4 is the gravel filling layer; 1-5 is the actual injection length; 1-6 is the design injection length; 1-7 is the flow control screen; 1-8 is the sealing particle; 1-9 is the oil producing layer; 1-10 is the choke ring; 1-11 is the effluent layer; For the open hole wall; 1-13 for the working column; 1-14 for the mixing tank. At the same time, the injection method is to inject into the target layer through the entire string, and the length of the string is generally several kilometers or even several kilometers, and the flow-blocking medium enters the target layer through such a long pipeline, which also causes the flow-blocking medium. Great waste. In addition, the method of injecting liquid from the wellhead requires setting up a large liquid mixing tank on the ground for agitation, which requires a large amount of resources and is inconvenient to operate.

The above problems with the injection method are as follows:

(1) It can not be quantified, there are excessive injection and under-injection; excessive injection will cause excessive injection of working agent in the underground circulation, which will affect the annulus and mining level. Excessive injection of glue will seriously affect the production of oil recovery and production. Process, such as excessive injection of colloid, glue will enter the oil layer, affecting oil flow out of the formation, reducing mining efficiency; under-injection can not achieve the purpose of injection;

(2) The colloid is transported along the injection pipe for a long distance, which will be contaminated by impurities in the working pipe column, which will adversely affect the rubber performance; affect the working efficiency of the working fluid, such as the adhesive performance is greatly reduced, and the effect of the injection operation is generated. Negative Effects;

(3) The working fluid is transported over a long distance in the conveying pipe, the working fluid is polluted and the formation is polluted, resulting in a decrease in formation production, which adversely affects the normal operation of oil production and gas production;

(4) The amount of glue used is large, and the ground glue equipment is bulky. In this way, the glue must be injected through the long-distance injection tube, causing a large waste of glue;

(5) When the method is simultaneously injected in multiple layers, there is a problem that the amount of injected glue cannot be controlled hierarchically. Because different layers, the amount of glue required is very different. In order to achieve better results, layered injection is generally used, that is, one layer is injected, one column is moved, the workload is large, and the efficiency of injection operation is low. Meet the requirements of efficient operation.

Taking vertical well injection as an example, the vertical well has five layers, the oil layer is 3 meters thick, and there are three compartments. The compartment is 2 meters thick and the depth is 3000 meters. The well is a gravel filling well. If the rubber ring is 2 meters high. The real effective demand is 20L, but the use of ground injection requires thousands of liters of glue, because it takes into account the amount of glue lost on the wall of the upper kilometer. And this method requires the ground pumping equipment to inject the glue into the well, the precision of the injected glue can not be accurately controlled, and it is easy to cause pollution; the dirt on the inner wall of the pipeline along the way, such as rust, will cause fouling of the glue, and the performance of the chemical agent is greatly reduced. ; use pre- and post-liquid The slug-type conveying glue will cause the problem that the pre-liquid and the post-liquid are mixed with each other. When the rubber injection pipe string is dragged, the positioning accuracy is low and the error is large, which can not meet the position accuracy requirement of the underground injection operation; this operation mode can only inject the glue into a layer at a time, and the layer needs to be dragged by one layer. The construction work time is long; the ground injection equipment is bulky, and the operation process of the injection operation is complicated.

In addition to the injection molding operation, there are other working fluid injections, such as deblocking liquid, descaling liquid, repair liquid, oxidant, etc., such as oxidant, which is easy to explode when carried, and the carrying amount is small, and the problem cannot be solved. Therefore, the injection of these working fluids by the ground injection method also has the problem of requiring precise control of the injection amount.

Therefore, in order to solve the above problems, it is necessary to design a working agent injection system and an injection method capable of accurately and quantitatively injecting a medium and capable of being accurately positioned.

Summary of the invention

The technical problem to be solved by the present invention is to overcome the defects of the prior art, and provide a storage precision quantitative oil and gas well working agent injection system and an injection method thereof. The storage type precision quantitative oil and gas well working agent injection system adopts a working agent memory which can be pre-quantized and injected into the working agent, can accurately inject the working agent, ensure the precision of the injection amount of the working agent, and ensure the injection work of the underground working agent. High efficiency and accuracy; no waste of working agent, avoiding a large amount of waste of working agent in the injection pipe of the traditional injection operation, improving the utilization rate of the working agent and reducing the operation cost; after the injection operation is completed, It can be used again after being taken out, and the working agent injection system has the characteristics of repeated use, which reduces the cost of the injection operation and improves the work efficiency;

The invention utilizes the injection method of the storage precision quantitative oil and gas well working agent injection system, can accurately and quantitatively inject the working agent into the target position, has excellent injection precision and position accuracy, ensures the optimal injection effect; The packer can seal the working agent in the annulus of the target position, and there is no turbulence of the working agent, which ensures the normal production operation in the underground, and does not cause the layer outside the target position to be affected by the working agent.

In order to solve the above problems, the technical solution adopted by the present invention is:

A storage precision quantitative oil and gas well working agent injection system, the injection system comprising an injection pipe and a ground pressurizing device, wherein one or more sets of injection units are provided in the injection pipe; each set of injection units comprises a variable volume working agent storage a working agent discharge port connected to the outside of the injection pipe on the injection pipe, the discharge port being connected to the working agent storage; the ground pressing device is generated in the injection pipe to act on the variable volume working agent storage, higher than the injection The pressure outside the tube, the volume of the variable volume of the working agent is reduced, and the working agent flows out through the discharge port to the outside of the injection tube.

Each injection unit of the working agent injection system carries a working agent memory, and the working agent memory carries a pre-quantitative The stored working agent, wherein the working agent can be a liquid and a gel-like working agent; after the injection tube is lowered to the target position, pressure is applied to the working agent storage through the ground pressing device, so that the working agent in the working agent memory passes through The discharge port flows to a target position outside the injection pipe to complete the injection of the working agent.

The types of working agents used in the present invention include the following:

(1) a flow-blocking medium: characterized by hypotonicity or non-permeability, and its components include and are not limited to one or more of the following: gel, resin, cement, polymer, and infiltration inhibitor;

(2) formation sand consolidation agent, descaling agent, deblocking agent, oxidant;

(3) Acid solution: The composition thereof is not limited to one or more of the following: hydrochloric acid, sulfuric acid, hydrogen peroxide.

The technical solution of the invention pre-quantizes the working agent in the working agent memory, and discharges it to the target position through the injection pipe to perform the working agent injection operation, thereby realizing accurate quantitative injection of the working agent without causing waste of the working agent, and the operation mode Simple and efficient, low operating costs.

Preferably, the working agent memory is a capsule memory. The capsule memory can be made of a deformable material such as rubber, plastic or airtight cloth. After being subjected to the pressure of the ground pressing device, the volume of the capsule memory shrinks and the internal working agent is discharged through the discharge port. Go to the target location and complete the work agent injection operation.

Preferably, the capsule memory is internally provided with a liquid guiding tube communicating with the outlet of the capsule memory, and the liquid guiding tube is provided with a plurality of liquid guiding holes. Since the volume of the capsule memory is reduced by the pressure, the side wall of the capsule memory is likely to cause the internal working agent to be completely discharged. Therefore, the design of the liquid guiding hole can ensure the volume of the capsule memory is reduced. It will not cause the discharge failure of the working agent, and ensure that the discharge channel of the working agent is unobstructed. The liquid guiding tube prevents the capsule from being deformed by the portion closer to the outlet end and sealing the outlet to block the extrusion of the working agent at other portions. The draft tube can be a metal tube or a rubber tube or a plastic tube.

Preferably, the working agent reservoir is a cylinder liner and a piston type memory. The invention can also select a cylinder sleeve and a piston type storage to store the working agent, and the working agent is pre-quantized and stored in the cylinder liner, and after being placed under the injection pipe to the target position, the piston is pressurized by the ground pressing device to make the piston The work agent in the cylinder liner is pushed out to the target position through the discharge port to complete the injection work of the working agent. The cylinder liner is made of metal, and the piston can be made of metal or rubber or plastic. The cylinder liner and the piston storage are kept sealed throughout the operation, and the working agent can only be extruded from the discharge port.

For the above two types of work agent memories, a capsule memory is generally preferred. Comparing the two memories, the capsule memory has the following advantages:

1. Large capacity, the length of the capsule memory can be more than ten meters or even tens of meters, and it is difficult to achieve this length for the cylinder liner and the piston memory.

2. The volume can be flexibly adjusted, and the capsule memory can be connected arbitrarily, and the structure is limited, and the cylinder liner and the piston memory are difficult to realize.

3. Low cost. The capsule memory is made of rubber extruded through a die, while the cylinder liner and piston reservoir are made of metal and require machining.

4. Easy to install and operate.

5. Easy to maintain. After the capsule storage is used, it is only necessary to replace the new rubber bladder when using the cylinder, and the cylinder liner and the piston storage need to clean the cylinder, especially to clean the solidified colloid.

6. Can achieve a smaller outer diameter size, can be used in small size downhole string.

Preferably, a constant pressure valve is arranged on the discharge port. The ground pressing device applies pressure to the working agent storage. When the pressure increases to the working pressure of the constant pressure valve, the constant pressure valve opens, so that the working agent in the working agent reservoir flows out from the discharge port to the target position. The structure of the constant pressure valve can ensure the quantitative and effective preservation of the working agent in the working agent memory, without causing the overflow of the working agent and ensuring accurate quantification.

The constant pressure valve here can also be replaced by other types of valves, such as hydraulic opening, pneumatic opening, pressure rupture diaphragm type valve instead of achieving this function.

Preferably, the working agent memory is provided with an injection port for injecting a working agent into the working agent memory. A check valve is disposed on the injection port to ensure that the working agent injected into the working agent reservoir does not flow out from the injection port, thereby ensuring strict and accurate quantification of the working agent.

Preferably, in the technical solution of the present invention, the positioning device can be used to achieve precise positioning, and the positioning device is fixed on the working tube string, and the positioning is performed through the downhole tubular string that has been lowered to ensure the accuracy of the injection position. The commonly used method is to set a shoulder, a tapered surface, etc. on the inner tubular string, and a shoulder or a tapered surface matching the shoulder and the taper surface is arranged on the working tubular string, and the positioning surface and the injection port are designed accurately. Guarantee accurate positioning. It is also possible to position the bottom of the working pipe column and the bottom of the downhole pipe string, and the design of the bottom of the injection pipe and the bottom of the working pipe string and the distance of the bottom of the downhole pipe string are accurately matched, and the precise positioning can also be ensured.

Preferably, the technical solution of the present invention further includes a packer, and a packer is disposed on the outer side of the injection pipe of the upper side and the lower side of the discharge port of each injection unit, and after the packer is expanded, the packer can be The annulus at the discharge port is isolated to form a closed space, so that the squeezed working agent in the working agent memory can only enter the target position, and no work will occur. The turbulent phenomenon of the agent ensures the accuracy of the injection of the working agent and avoids the turbulence of the working agent, which adversely affects the production operation in the underground.

The packer employed in the present invention may be in the form of a cup packer or a dilator packer.

Preferably, a set of drains is installed at the end of the working agent injection system. The oil drainer is closed during the injection of the working agent. When the injection operation is completed, the oil drainer can be opened by pressure or pressure pulse or other means that can be opened, so that the inside of the injection pipe communicates with the outside, and the internal and external pressures are restored. Balance, so that the packer is pressure-retracted and retracted, and the pressurized medium in the column is removed to facilitate the starting of the working string.

The oil drainer can be a pin-cut type drain valve or an intelligent pressure-controlled switch that can be opened with a pressure pulse. The pressure-controlled switch can be repeatedly opened and closed. This function can be achieved by installing a set of oil drainers only at the end of the tool, whether it is a single or multiple injection unit.

The ground pressing device adopted by the technical scheme of the present invention comprises a high-pressure fluid injection device commonly used in oil fields such as a pump truck, a fracturing truck and a cement truck;

The invention also discloses an injection method using a storage type precise quantitative oil and gas well working agent injection system, which is to pre-quantify the working agent into the variable volume working agent storage on the ground, and lower the injection pipe to the underground Target position; the ground pressurizing device generates a pressure on the variable-volume working agent reservoir above the injection tube in the injection tube, the volume of the variable-volume working agent is reduced, and the working agent flows out through the discharge port To the outside of the injection tube.

The specific steps of the injection method are:

(1) pre-quantizing the working agent into the variable volume working agent reservoir in the injection tube on the ground; injecting the working agent into the working agent memory according to the amount of the working agent required at the predetermined target position;

(2) The packer is connected in series above and below the discharge port of the injection pipe; the packer is used for the annular space at the target position in the downhole to avoid turbulence of the working agent and ensure the accuracy of the injection of the working agent;

(3) connecting the injection pipe and the feeding pipe to form a working pipe string; according to the depth of the target position, the injection pipe and the feeding pipe are connected in series as a working pipe string, and the injection pipe is lowered to the target position through the feeding pipe;

(4) Lower the injection pipe to the downhole so that the discharge port is aligned with the target position to achieve precise positioning;

(5) Apply pressure to the injection pipe through the ground pressurizing device, and continuously pressurize, so that the pressure inside the injection pipe is higher than the pressure outside the injection pipe; at this time, the packer expands under the action of pressure, and the target position is up and down. Square annulus;

(6) When the pressure in the injection pipe reaches the working pressure of the discharge port constant pressure valve, the constant pressure valve opens, and the working agent memory The working agent flows out from the discharge port and is injected into the target position through the annulus between the packers; the expansion pressure of the packer is less than the working pressure of the constant pressure valve, that is, the packer first expands and then the pressure continues. After the increase, the constant pressure valve is opened to start the working agent injection operation;

(7) The pressure in the injection pipe presses the working agent memory, so that the working agent is extruded through the discharge port until the volume of the working agent storage is no longer reduced, and the injection operation is completed. Under the action of the packer, the working agent is accurately injected at the target position, and the working agent does not cause turbulence, ensuring the accuracy of the injection of the working agent and the accuracy of the injection amount.

The advantages and benefits of the present invention are:

The storage precision quantitative oil and gas well working agent injection system of the invention adopts a working agent storage device capable of pre-quantizing the working agent, can accurately inject the working agent, ensure the precision of the injection of the working agent, and ensure the injection work of the underground working agent. Efficient and accurate;

The storage precision precise quantitative oil and gas well working agent injection system pre-quantizes and stores the working agent in the working agent memory, and is discharged to the target position for injection operation, which does not cause waste of the working agent, and avoids the injection pipe of the traditional injection operation. The large amount of waste of the working agent improves the utilization rate of the working agent and reduces the operating cost;

The storage type precision quantitative oil and gas well working agent injection system of the invention can be taken out and reused after the injection operation is completed, and the working agent injection system has the characteristics of repeated use, which reduces the cost of the injection operation and improves the operation efficiency;

Further, for a gel which is formed by mixing a gel main body and one or more crosslinking initiators to form a settable gel, it gradually solidifies in a certain period of time. If the glue is pre-mixed on the ground and then lowered into the well, the glue will solidify before the injection operation, and it will not be squeezed out of the working agent memory, resulting in failure of the operation. In order to solve this problem, the present invention also discloses an injection method using a storage type precise quantitative oil and gas well working agent injection system, which is used for injecting glue into an underground target position. For convenience of description, the following describes the glue body. And a cross-linking initiator is mixed, the gel body is abbreviated as A agent, and the cross-linking initiator is abbreviated as B agent, and the glue is prepared by mixing A agent and B agent in proportion. In the ground, the agent A and the agent B are respectively dosed into two different variable volume working agent storages according to a predetermined ratio, and the one agent valve outlet and the B agent memory outlet are respectively provided with a one-way valve and a corresponding proportion of the flow regulator, A Agent storage The outlet of the device and the outlet of the B agent reservoir are in communication with each other. In addition, the cavity between the A agent storage outlet and the B agent storage outlet and the discharge port may be pre-filled with the blocking liquid, and combined with the check valve to separate the A agent and the B agent to prevent the glue injection operation. The A agent and the B agent may be mixed in advance; or the A agent and the B agent may be separated by only one-way valve. Then, the injection tube is lowered to a target position downhole; the ground pressurizing device generates a pressure on the variable agent working medium reservoir above the injection tube in the injection tube, and the volume of the variable volume working medium is reduced. First, the partition liquid is extruded, and the A agent and the B agent are respectively passed through the respective flow regulators, and are mixed into the flow channel at a predetermined proportion of the flow rate, and then the mixed working agent flows out to the outside of the injection pipe through the discharge port. In addition, if the glue is a mixture of a glue main body and one or more crosslinking initiators, it is necessary to inject the glue body and each crosslinking initiator into two or more working agent memories, respectively.

DRAWINGS

Figure 1 is a schematic view of the structure in the background art.

2 is a schematic structural view of a single group injection unit in Embodiment 1 of the present invention.

FIG. 3 is a schematic structural diagram of an injection system of three groups of injection units used in Embodiment 1 of the present invention.

4 is a schematic structural view of a single group injection unit in Embodiment 2 of the present invention.

FIG. 5 is a schematic structural diagram of an injection system of a single group injection unit according to Embodiment 2 of the present invention.

Fig. 6 is a schematic view showing the downhole state before the injection of the working agent after the injection tube is placed in position in the embodiment 3 of the present invention.

Figure 7 is a schematic view showing the downhole state of the injection tube after the injection tube is placed in position in the embodiment 3 of the present invention.

Fig. 8 is a schematic view showing the downhole state before the working agent is extruded after the injection tube is placed in position in the embodiment 4 of the present invention.

Figure 9 is a schematic view showing the downhole state of the injection tube after the injection tube is placed in position in the embodiment 4 of the present invention.

FIG. 10 is a schematic structural diagram of an injection system of three sets of injection units used in Embodiment 7 of the present invention.

11 is a schematic structural view of a single group injection unit in Embodiment 7 of the present invention.

Figure 12 is a schematic view showing the downhole state before the injection operation in the eighth embodiment of the present invention.

Figure 13 is a schematic view showing the downhole state after the injection operation in the eighth embodiment of the present invention.

Specific implementation

The invention is further illustrated by the following examples.

Example 1

This embodiment is a storage type precision quantitative oil and gas well working agent injection system, as shown in FIG. 3, the working agent injection system of the three types of injection unit capsule storage, 3-1 is the feeding tube; 3-2 is Injection tube; 3-3 is a packer; 3-4 is a discharge port; 3-5 is a constant pressure valve; 3-6 is a liquid guiding tube; 3-7 is a working agent memory; 3-8 is a working agent; 3-9 is the injection port; 3-10 is the oil drainer; 3-11 pressure transmission hole; 3-12 protective sleeve. The injection system comprises an injection tube and a ground pressing device, and the injection tube is provided with three sets of injection units; each group of injection units comprises a variable volume working agent storage, and a working agent discharge arranged on the injection tube and communicating with the outside of the injection tube a port, the discharge port is connected to the working agent storage; the ground pressing device generates a pressure on the working volume of the variable volume working agent outside the injection pipe in the injection pipe, and the volume of the variable volume working agent is reduced, The working agent flows out to the outside of the injection pipe through the discharge port. The ground pressurizing device used in this embodiment is a pump truck, and pressure is applied by injecting water into the injection pipe.

The working agent memory is a capsule memory. The capsule memory is internally provided with a liquid guiding tube communicating with the outlet of the capsule memory, and the liquid guiding tube is provided with a plurality of liquid guiding holes. A constant pressure valve is arranged on the discharge port. An injection port for injecting a working agent into the working agent reservoir is provided on the working agent reservoir. The outer surface of the capsule has a protective sleeve, which is generally made of a thin metal plate. Each group of injection units is provided with a pressure transmission hole, and the fluid pressure injected into the column by the ground pressure device can be smoothly transmitted to the bottom of the column.

2 is a schematic structural view of a single injection unit of the present embodiment, in which: 2-1 is a packer; 2-2 is a liquid guide; 2-3 is a working agent; 2-4 is a check valve; -5 is the oil drainer; 2-6 is the working agent memory; 2-7 is the constant pressure valve; 2-8 is the discharge port; 2-9 is the injection pipe; 2-10 is the protective cover; 2-11 is the transmission Pressing holes.

Example 2

The embodiment is a storage type precision quantitative oil and gas well working agent injection system, as shown in FIG. 5 is a group of injection unit cylinder liner and piston type working agent injection system, 5-1 is an oil drainer; -2 is the positioning device; 5-3 is the feeding tube; 5-4 is the packer; 5-5 is the discharge port; 5-6 is the constant pressure valve; 5-7 is the cylinder liner; 5-8 is the work 5-9 is a piston; 5-10 is a one-way valve; 5-11 is a sealing screw; 5-12 is an injection tube; 5-13 is a pressure transmission hole. The injection system comprises an injection tube and a ground pressing device, wherein the injection tube is provided with a group of injection units; each group of injection units comprises a variable volume working agent storage, and a working agent discharge arranged on the injection tube and communicating with the outside of the injection tube a port, the discharge port is connected to the working agent storage; the ground pressing device generates a pressure on the working volume of the variable volume working agent outside the injection pipe in the injection pipe, and the volume of the variable volume working agent is reduced, The working agent flows out to the outside of the injection pipe through the discharge port. The ground pressurizing device used in this embodiment is a pump truck, and pressure is applied by injecting water into the injection pipe. After the injection operation is completed, the water sent into the tube is connected to the outside of the feeding tube through the oil drainer, and the pressure in the feeding tube is removed to solve the packer solution. Sealed, easy to feed the tube out of the well. The working agent storage is cylinder liner and piston type. A constant pressure valve is arranged on the discharge port. An injection port for injecting a working agent into the working agent reservoir is provided on the working agent reservoir. Each group of injection units is provided with a pressure transmission hole, and the fluid pressure injected into the column by the ground pressure device can be smoothly transmitted to the bottom of the column.

4 is a schematic structural view of a single injection unit used in the present embodiment. In FIG. 4: 4-1 is an injection pipe; 4-2 is a packer; 4-3 is a discharge port; 4-4 is a constant pressure valve. 4-5 is the cylinder liner; 4-6 is the working agent; 4-7 is the one-way valve; 4-8 is the piston; 4-10 is the pressure transmission hole.

Example 3

An injection method using a storage type precise quantitative oil and gas well working agent injection system, wherein the injection agent is pre-quantized into a variable volume working agent storage on the ground, and the injection pipe is lowered to a target position under the well; The pressurizing device generates a pressure on the working volume of the variable volume above the injection tube in the injection tube, the volume of the variable volume working agent is reduced, and the working agent flows out through the discharge port to the outside of the injection tube. The ring is empty.

In the third embodiment, the injection operation is performed by using the working agent injection system of the three types of injection units of the first embodiment, and the present embodiment is performed in the horizontal well of the bottom water reservoir, in order to prevent the coning of the bottom water. In the case where the composite screen has been completed and the outer annulus of the screen is filled with gravel, the gel is carried by the downhole quantitative injection tool. The containment is formed at three target locations to prevent axial turbulence of the formation fluid within the wellbore.

As shown in Figure 6, the schematic diagram of the downhole state before the injection operation, in Figure 6: 6-1 is the top packer; 6-2 is the gravel pack; 6-3 is the discharge port; 6-4 is the injection pipe 6-5 is the target position; 6-6 is the capsule memory; 6-7 is the oil drainer; 6-8 is the open hole wall; 6-9 is the working agent; 6-10 is the liquid guiding tube; 6-11 It is a packer; 6-12 is a positioning device; 6-13 is a feeding tube.

The specific steps of the injection method are:

(1) pre-quantizing the working agent into the variable volume working agent reservoir in the injection tube on the ground; the working agent injected into each working agent memory is 22.5L;

(2) respectively connecting the packers in series above and below the discharge port of the injection pipe;

(3) connecting the injection pipe and the feed pipe to form a work pipe string;

(4) lowering the injection pipe to the downhole, so that the discharge port is aligned with the target position; determining the target position through the positioning device on the work pipe string, so that the discharge port corresponds to it;

(5) applying pressure to the injection pipe through the ground pressing device, continuously pressurizing, so that the pressure inside the injection pipe is higher than the pressure outside the injection pipe; in this embodiment, the pump truck is used to apply water and pressure to the injection pipe;

(6) When the pressure in the injection pipe reaches the working pressure of the constant pressure valve at the discharge port, the constant pressure valve opens, and the working agent in the working agent memory flows out from the discharge port, and is injected into the target through the annulus between the packers. Position; the working pressure of the packer is less than the working pressure of the constant pressure valve, that is, when the local surface pressing device is continuously pressurized, the pressure is increased to 2 MPa, the expansion packer is set, and then the pressure is continuously increased to reach the constant pressure valve. The working pressure is 2.5 MPa, and then the constant pressure valve is opened for the working agent injection operation;

(7) The pressure in the injection pipe presses the working agent memory to extrude the working agent until the volume of the working agent storage is no longer reduced, and the injection operation is completed. When the working agent is injected into the working agent memory in advance, the residual amount of the final non-extrudable in the working agent reservoir and the discharge port is calculated to ensure accurate quantitative injection of the injected working agent.

After the injection operation is completed, the decompressor is depressurized to depressurize the packer, so that the injection pipe and the feed pipe are taken out from the well.

As shown in Figure 7, the schematic diagram of the downhole state after the completion of the injection operation, in Figure 7: 7-1 is the top packer; 7-2 is the gravel pack; 7-3 is the discharge port; 7-4 is compressed Capsule memory; 7-5 is the target position; 7-6 is the packer; 7-7 is the oil drainer; 7-8 is the open hole wall; 7-9 is the positioning device; 7-10 is the feed pipe. The agent is precisely dosed at three target locations downhole.

Example 4

In the fourth embodiment, the injection processing system of the capsule memory of the three groups of injection units described in Embodiment 1 is used for the injection operation, and the embodiment is performed in the vertical well of the heavy oil casing perforation, in order to control the water and sand control, Does not affect the oil production, in the case that the composite screen is completed and the outer ring of the screen is filled with the packing particles, the solidified polymer is carried by the downhole quantitative working tool, and three different in the sealing particles The polymer is injected into the target at a depth, and after it solidifies, a choke ring is simultaneously established.

As shown in Fig. 8, the schematic diagram of the downhole state before the injection operation, in Fig. 8: 8-1 is the casing wall; 8-2 is the feeding pipe; 8-3 is the positioning device; 8-4 is the top isolation 8-5 is a gravel filling layer; 8-6 is a discharge port; 8-7 is a capsule memory; 8-8 is a target position; 8-9 is a packer; 8-10 is a perforation tunnel; -11 is the working agent; 8-12 is the oil drainer; 8-13 is the liquid guiding tube; 8-14 is the sand control screen tube string.

The specific steps of the injection method are:

(1) Pre-quantitatively injecting the working agent into the variable-volume working agent reservoir in the injection tube on the ground; the working agent injected into each working agent memory is 20L polymer; the required choke ring has a length of 2m, each target The required polymer volume at the location is 15L.

(2) The packer is connected in series above and below the discharge port of the injection pipe; the packer is an expanded packer.

(3) connecting the injection pipe and the feed pipe to form a work pipe string;

(7) The pressure in the injection pipe presses the working agent memory to extrude the working agent until the volume of the working agent storage is no longer reduced, and the injection operation is completed. When the working agent is injected into the working agent memory in advance, the residual amount of the final non-extrudable in the working agent reservoir and the discharge port is calculated to ensure accurate quantitative injection of the injected working agent. In this embodiment, 15 L of polymer is required for each target position, and 20 L of polymer is pre-filled in each of the working agent memories.

After the injection operation is completed, the decompressor is depressurized to depressurize the packer, so that the injection pipe and the feed pipe are taken out from the well. After about 24 hours of shutting down the well, the polymer injected into the blocking particles will automatically solidify into a solid, forming a stable choke.

As shown in Fig. 9, the schematic diagram of the downhole state after the completion of the injection operation, in Fig. 9: 9-1 is the casing wall; 9-2 is the feeding pipe; 9-3 is the positioning device; 9-4 is the top packer 9-5 is the gravel filling layer; 9-6 is the discharge port; 9-7 is the capsule memory; 9-8 is the target position; 9-9 is the packer; 9-10 is the perforation channel; 9- 11 is the oil drainer; 9-12 is the liquid guiding tube; 9-14 is the sand control screen tube string. Accurate quantitative injection of the settable polymer into the three target locations downhole to form three choke rings.

Example 5

On the basis of Embodiment 3, another embodiment of the present invention is an injection method using a storage type precise quantitative oil and gas well working agent injection system; the working agents in the three capsule memories of the method are respectively Formation sand consolidation agent, cement and hydrogen peroxide; one-time lower injection pipe can realize three formations and simultaneously inject three different working agents, which greatly improves the operation efficiency and reduces the operation cost;

The ground pressing device is a pump truck, and pressurizes the injection tube to squeeze the working agent out of the capsule memory;

The packer uses a cup-shaped packer;

The other parts are identical to the embodiment 3.

Example 6

On the basis of Embodiment 4, another embodiment of the present invention is an injection method using a storage type precision quantitative oil and gas well working agent injection system; the working agent memory used in the method is a cylinder liner and a piston memory. The working agents in the three cylinder liners and the piston type memory are detergent, gel and resin respectively; the one-time lowering of the feeding tube and the injection tube can realize the injection operation of three different working agents in three formations at the same time. Greatly improve work efficiency and reduce operating costs;

The ground pressing device is a fracturing vehicle on the ground, and the fracturing truck pressurizes the injection pipe to extrude the working agent from the cylinder liner and the piston type storage;

The packer uses an expanded packer;

The other parts are identical to the embodiment 4.

Example 7

This embodiment is a storage type precision quantitative oil and gas well working agent injection system, as shown in FIG. 10 is a working medium injection system of a three-group injection unit capsule, 10-1 is a feeding tube; 10-2 is Injection tube; 10-3 is packer; 10-4 is discharge port; 10-5 is constant pressure valve; 10-6 is liquid guide tube; 10-7 is A working agent memory; 10-8 is working for A 10-9 is the injection port; 10-10 is the oil drainer; 10-11 is the B working agent memory; 10-12 is the B working agent; 10-13 is the flow regulator A; 10-14 is the flow regulator B. The injection system includes an injection tube and a ground pressurizing device, and the injection tube is provided with three sets of injection units; each set of injection units includes a variable volume A working agent memory and a B working agent memory, which are disposed on the injection tube and outside the injection tube a working working material discharge port, the discharge port and the A and B working agent memories are connected to each other; the ground pressing device generates a pressure on the variable volume working agent storage device outside the injection pipe in the injection pipe, The variable volume working agent storage volume is reduced, and the working agent flows out to the outside of the injection pipe through the discharge port. The ground pressing device used in this embodiment is a pump truck, and pressure is applied by injecting water into the injection pipe.

The A, B working agent memory is a capsule memory. The capsule memory is internally provided with a liquid guiding tube communicating with the outlet of the capsule memory, and the liquid guiding tube is provided with a plurality of liquid guiding holes. A constant pressure valve is arranged on the A and B working agent memories. An injection port for injecting a working agent into the working agent memory is provided on the A and B working agent memories.

Figure 11 is a schematic structural view of a single injection unit of the present embodiment, in Figure 11: 11-1 is a packer; 11-2 is a liquid guiding tube; 11-3 is a working agent; 11-4 is a one-way valve; 11-5 is the oil drainer; 11-6 is the A working agent memory; 11-7 is the constant pressure valve; 11-8 is the discharge port; 11-9 is the injection pipe; 11-10 is the A working agent memory; -11 is the A working agent; 11-12 is the flow regulator A; 11-13 is the flow regulator B.

Example 8

An injection method using a storage type precise quantitative oil and gas well working agent injection system for injecting a cement into a subterranean oil layer, wherein the glue is prepared by mixing Promixed Agent A and Agent B. The injection method is to quantitatively inject the agent A and the agent B into the variable volume working agent storage according to a predetermined ratio of 1:50 on the ground, and the one-way valve and the corresponding proportion of the flow regulator are respectively disposed at the A-agent storage outlet and the B-agent outlet. The A agent storage outlet and the B agent storage outlet and the discharge port communicate with each other, but the cavity between the A agent storage outlet and the B agent storage outlet and the discharge port is filled with a partition liquid in advance to separate The A agent and the B agent prevent the A agent and the B agent from being mixed in advance before the injection molding operation, which causes the colloid to solidify and block the discharge port, so that the colloid cannot be injected into the annulus. Then, the injection tube is lowered to a target position downhole; the ground pressurizing device generates a pressure on the variable agent working medium reservoir above the injection tube in the injection tube, and the volume of the variable volume working medium is reduced. First, the partition liquid is extruded, and the A agent and the B agent are respectively passed through the respective flow regulators, and are mixed into the flow channel at a predetermined proportion of the flow rate, and then the mixed working agent flows out to the outside of the injection pipe through the discharge port. The benefits of mixing A and B in the ground: 1A and B can only form a gel that can be solidified in a certain period of time after mixing; 2 If A and B are mixed on the ground, due to the glue after mixing The Houning time is short, and it solidifies in advance during the process of entering, causing the operation to fail. When the target agent is placed in the target position of the embodiment, the agent A and the agent B are mixed into a glue, and the target is directly injected into the target position, thereby avoiding the problem that the glue is solidified in advance.

In the eighth embodiment, the working agent injection system of the capsule memory of the three groups of injection units described in Embodiment 7 is used for the injection operation, and the embodiment is carried out in the vertical bore of the casing perforation, in order to control the water and sand control, and does not affect at the same time. The amount of oil produced, in the case where the composite screen has been completed and the outer ring of the screen is filled with the packing particles, the agent A and the agent B are carried by the downhole quantitative infusion tool, and the agent A and the agent B are mixed in proportion to form Coagulable glue that simultaneously builds resistance at three different depths in the encapsulating particles Flow ring.

As shown in Fig. 12, the schematic diagram of the downhole state before the injection operation, in Fig. 12: 12-1 is the casing wall; 12-2 is the feeding pipe; 122-3 is the positioning device; 12-4 is the top packer 12-5 is the gravel filling layer; 12-6 is the discharge port; 12-7 is the capsule memory A; 12-8 is the target position; 12-9 is the packer; 12-10 is the perforation channel; -11 is the A working agent; 12-12 is the oil drainer; 12-13 is the liquid guiding tube; 12-14 is the capsule memory B; 12-15 is the B working agent; 12-16 is the flow regulator A; -17 is the flow regulator B.

The specific steps of the injection method are:

(1) The A agent and the B agent are quantitatively injected into the variable volume working agent storage according to a predetermined ratio of 1:50 on the ground, and the check valve and the corresponding proportion of the flow regulator are respectively disposed at the A agent storage outlet and the B agent storage outlet. The A agent storage outlet and the B agent storage outlet and the discharge port communicate with each other, but the cavity between the A agent storage outlet and the B agent storage outlet and the discharge port is filled with a liquid in advance;

(3) connecting the injection pipe and the feed pipe to form a work pipe string;

(5) applying pressure to the injection pipe through the ground pressing device, continuously pressurizing, so that the pressure inside the injection pipe is higher than the pressure outside the injection pipe; in this embodiment, the fracturing vehicle is used to apply water and pressure to the injection pipe;

(6) When the pressure in the injection pipe reaches the working pressure of the constant pressure regulating valve of the discharge port, the constant pressure valves are simultaneously opened, and the agent A and the agent B are discharged from the respective working agent memories through the flow regulator and mixed in the flow channel. The solidizable glue, and then the glue flows out from the discharge port and is injected into the target position through the annular space between the packers; the working pressure of the packer is less than the working pressure of the constant pressure valve, that is, the local surface pressing device When continuously pressurized, the pressure is increased to 2 MPa, and the expansion packer is set. After the pressure is continuously increased, the working pressure of the constant pressure valve is 2.5 MPa, and then the constant pressure valve is opened to perform the working agent injection operation;

(7) The pressure in the injection pipe presses the working agent memory to extrude the working agent until the volume of the working agent storage is no longer reduced, and the injection operation is completed. When the working agent is injected into the working agent memory in advance, the residual amount of the final non-extrudable in the working agent reservoir and the discharge port is calculated to ensure accurate quantitative injection of the injected working agent. In this embodiment, 25L glue is required for each target position, and the loss needs to carry 30L of glue. According to the ratio of 1:50, it is necessary to pre-fill 0.6L A agent and 29.4L B agent in different working agent memories.

After the injection operation is completed, the decompressor is depressurized to depressurize the packer, and the injection pipe and the feed pipe are taken out from the well. Shujing After about 24 hours, the polymer injected into the encapsulating particles will automatically solidify into a solid, forming a stable choke.

As shown in Fig. 13, the schematic diagram of the downhole state after the completion of the injection operation, in Fig. 13: 13-1 is the casing wall; 13-2 is the feeding pipe; 13-3 is the positioning device; 13-4 is the top packer 13-5 is a gravel filling layer; 13-6 is a discharge port; 13-7 is a capsule memory A; 13-8 is a target position; 13-9 is a packer; 13-10 is a perforation tunnel; -11 is the A working agent; 13-12 is the oil drainer; 13-13 is the liquid guiding tube; 13-14 is the capsule memory B; 13-15 is the B working agent; 13-16 is the flow regulator A; 13 -17 is the flow regulator B. The polymer was precisely dosed at three target locations downhole to form three choke rings.

It should be noted that the above-described embodiments are merely illustrative of the invention and are not intended to limit the embodiments. Other variations or modifications of the various forms may be made by those skilled in the art in light of the above description. There is no need and no way to exhaust all of the implementations. Obvious changes or variations resulting therefrom are still within the scope of the invention.

Claims

A storage precision quantitative oil and gas well working agent injection system, the injection system comprising an injection pipe and a ground pressing device, wherein the injection pipe is provided with one or more groups of injection units; each group of injection units comprises a variable volume a working agent storage device, which is disposed on the injection pipe and communicates with the working agent discharge port outside the injection pipe, and the discharge port communicates with the working agent storage; the ground pressing device generates a working agent storage device for the variable volume in the injection pipe. Above the pressure outside the injection tube, the volume of the variable volume of the working agent is reduced, and the working agent flows out through the discharge port to the outside of the injection tube.
The storage precision quantitative oil and gas well working agent injection system according to claim 1, wherein the working agent memory is a capsule memory.
The storage type precision quantitative oil and gas well working agent injection system according to claim 2, wherein the capsule type memory is provided with a liquid guiding tube communicating with the outlet of the capsule memory, and the liquid guiding tube is provided with a plurality of liquid guiding tubes. hole.
The storage type precision quantitative oil and gas well working agent injection system according to claim 1, wherein the working agent memory is a cylinder liner and a piston type memory.
The storage type precision quantitative oil and gas well working agent injection system according to any one of claims 1 to 5, characterized in that the discharge port is provided with a constant pressure valve.
The storage type precision quantitative oil and gas well working agent injection system according to any one of claims 1 to 5, characterized in that the working agent memory is provided with an injection port for injecting a working agent into the working agent memory.
The storage type precision quantitative oil and gas well working agent injection system according to any one of claims 1 to 6, characterized in that the injection pipe is provided with two or more working agent memories, respectively carrying different working agents, two The memory outlet and the discharge port are connected to each other, and the flow agent is provided with a flow regulator. After the different working agents are discharged through the flow regulator, the mixed liquid is firstly mixed to form a mixed liquid, and then flows to the outside of the injection pipe.
An injection method using a storage type precision quantitative oil and gas well working agent injection system, wherein the injection method is to pre-quantify a working agent into a variable volume working agent storage on the ground, and lower the injection pipe to the underground Target position; the ground pressurizing device generates a pressure on the variable-volume working agent reservoir above the injection tube in the injection tube, the volume of the variable-volume working agent is reduced, and the working agent flows out through the discharge port To the outside of the injection tube.
The method according to claim 8, wherein the step of injecting the injection method is:

(1) pre-quantizing the working agent into the variable volume working agent reservoir in the injection tube on the ground;

(2) respectively connecting the packers in series above and below the discharge port of the injection pipe;

(3) connecting the injection pipe and the feed pipe to form a work pipe string;

(4) Lower the injection pipe to the well to align the discharge port with the target position;

(5) applying pressure to the injection pipe through the ground pressurizing device, continuously pressurizing, so that the pressure inside the injection pipe is higher than the pressure outside the injection pipe;

(6) When the pressure in the injection pipe reaches the working pressure of the constant pressure valve at the discharge port, the constant pressure valve opens, and the working agent in the working agent memory flows out from the discharge port, and is injected into the target through the annulus between the packers. position;

(7) The pressure in the injection pipe presses the working agent memory to extrude the working agent until the volume of the working agent storage is no longer reduced, and the injection operation is completed.