阅读说明：本技术 一种基于油管输送的页岩储层加热装置 (Shale reservoir heating device based on oil pipe conveying ) 是由 康毅力 李佩松 陈明君 游利军 刘江 赖哲涵 余中慧 陈文轩 刘雨婷 尚瑶瑶 于 2021-10-16 设计创作，主要内容包括：本发明涉及一种基于油管输送的页岩储层加热装置,包括主电缆、主体腔室、下压器、柔性电缆、上支撑架、加热电阻板、下支撑架、外部温压传感器、内部温压传感器、锚定装置和保护外壳。主体腔室与油管连通并基于油管输送至作业层位,主体腔室内部包含有与地面连接的主电缆和监测温度压力的内部温压传感器；主体腔室外部安装有稳定装置位置的锚定装置和实现高温作用的加热电阻板。加热电阻板通过与主电缆连接的柔性电缆供电,在下压器、上支撑架和下支撑架的作用下移动并贴近井筒,并运用外部温压传感器监控加热电阻板温度和主体腔室外部压力。本发明可为在页岩储层中安全、稳定、简便的储层热处理施工提供设备支撑。(The invention relates to a shale reservoir heating device based on oil pipe conveying, which comprises a main cable, a main cavity, a lower pressure device, a flexible cable, an upper support frame, a heating resistance plate, a lower support frame, an external temperature and pressure sensor, an internal temperature and pressure sensor, an anchoring device and a protective shell. The main body cavity is communicated with an oil pipe and is conveyed to an operation layer based on the oil pipe, and a main cable connected with the ground and an internal temperature and pressure sensor for monitoring temperature and pressure are contained in the main body cavity; the outside of the main body chamber is provided with an anchoring device for stabilizing the position of the device and a heating resistance plate for realizing high-temperature action. The heating resistance plate is powered by a flexible cable connected with the main cable, moves under the action of the lower pressure device, the upper support frame and the lower support frame and is close to the shaft, and the temperature of the heating resistance plate and the external pressure of the main cavity are monitored by using an external temperature and pressure sensor. The invention can provide equipment support for safe, stable and simple reservoir heat treatment construction in the shale reservoir.)

1. The shale reservoir heating device based on oil pipe conveying is characterized in that a main cable has power supply and signal transmission functions, the main cable is connected with a flexible cable, the flexible cable is connected with a heating resistance plate and provides electric energy, and the flexible cable is connected with an external temperature and pressure sensor and transmits a temperature and pressure signal to the main cable.

2. The heating resistor plate of claim 1, wherein the heating resistor plate, the upper support frame and the lower support frame form a telescopic linkage, the upper support frame is connected with the lower pressure device, and the lower pressure device axially expands and contracts under the action of the internal pressure of the main body cavity and pushes the heating resistor plate to radially expand and contract so that the heating resistor plate is close to the inner wall of the shaft.

Technical Field

The invention relates to a shale reservoir heating device based on oil pipe conveying, and belongs to the technical field of energy and environment.

Background

The shale gas reservoir has the characteristics of high clay mineral content, rich organic matters, compact base block, strong heterogeneity and the like, and the high-efficiency development must be realized by adopting a horizontal well and staged fracturing technology. The shale reservoir has long staged fracturing duration, a fracture network is formed after large-scale fracturing, the seepage quantity of the fracturing fluid is large, the flowback rate is low, and a large amount of fracturing fluid is retained in the reservoir. The retained fracturing fluid can induce water phase trapping damage and water sensitivity damage, and seriously restrict the permeability-increasing and yield-increasing effects of the hydraulic fracturing technology. How to greatly reduce the damage of the retained liquid phase and fully play the positive role of the retained fracturing fluid becomes a problem of particular attention of shale gas development.

The existing research shows that the temperature of the shale reservoir after hydraulic fracturing is improved to form thermally induced fractures, and a more complex fracture network can be formed on the basis of the hydraulic fractures. Meanwhile, the water phase trapping damage can be relieved under the action of high temperature, and the productivity of the gas well is released. When the temperature is raised to be higher than the critical temperature of water, namely 373.946 ℃, the water-based fracturing fluid retained in the reservoir can be converted into a supercritical state in situ by combining the current engineering situation that the pressure of the shale reservoir is more than the critical pressure of water, namely 22.064 MPa. The water-based fracturing fluid in a supercritical state has the same properties as supercritical water: low density, low viscosity, low mass transfer resistance, strong catalytic oxidizability, high gas and organic matter solubility and strong flowing ability. The water-based fracturing fluid converted into the supercritical state in situ is transported into the hydraulic fracture, so that the damage of water phase trapping in a near-wellbore area can be relieved, and methane adsorbed on the wall surface of pores and dissolved in kerogen can be dissolved, so that the transportation of the methane is promoted. In a word, the shale reservoir heat treatment process has considerable prospect.

Chinese patent: CN108505971A proposes a reservoir heating process and apparatus by injecting hot fluid, but for shale reservoir development with compact base block and developing nano pores, introducing a large amount of extraneous fluid such as high temperature steam may cause new damage to the reservoir. In the actual construction process, safe, efficient and reliable underground heating equipment and process are urgently needed to support the industrial application of the shale reservoir heat treatment process.

Disclosure of Invention

The shale reservoir heating device based on oil pipe conveying can be conveyed into a well through an oil pipe, and the shale reservoir can be safely, stably and simply heated.

In order to achieve the purpose, the invention adopts the technical scheme that:

a shale reservoir heating device based on oil pipe conveying comprises a main cable, a main body cavity, a lower pressure device, a flexible cable, an upper support frame, a heating resistance plate, a lower support frame, an external temperature and pressure sensor, an internal temperature and pressure sensor, an anchoring device and a protective shell.

The main cable is characterized by having power supply and signal transmission functions and being connected with the flexible cable.

The flexible cable is characterized in that the flexible cable is connected with the heating resistance plate and provides electric energy, and temperature and pressure signals of the external temperature and pressure sensor are transmitted to the main cable.

The external temperature and pressure sensor is characterized by being mounted on the heating resistance plate, used for monitoring the temperature of the heating resistance plate and the pressure of the external space of the main body cavity and transmitting data to the ground through the flexible cable and the main cable.

The internal temperature and pressure sensor is characterized by being mounted on the inner wall of the main body cavity and used for monitoring the internal temperature and pressure of the main body cavity and transmitting data to the ground through the flexible cable and the main cable.

The heating resistance plate is characterized in that a telescopic connecting rod mechanism is formed by the heating resistance plate, the upper support frame and the lower support frame, and the flexible cable is used for supplying power to the heating resistance plate so as to realize the rapid heating of the heating resistance plate and provide heat for a reservoir stratum.

The lower pressure device is characterized in that one end of the lower pressure device is in contact with the main body cavity, and the other end of the lower pressure device is connected with the upper support frame. Furthermore, the depressor axially stretches out and draws back under the action of the internal pressure of the main body cavity and pushes the heating resistance plate to radially stretch out and draw back, so that the heating resistance plate is close to the inner wall of the shaft.

The upper support frame is characterized in that the upper support frame is connected with the lower pressure device and the heating resistance plate, and the heating resistance plate is axially moved to be close to the inside of the shaft by being matched with the lower pressure device.

The lower support frame is characterized in that the lower support frame is connected with the protective shell and the heating resistance plate and is matched with the upper support frame to maintain the stability of the heating resistance plate.

The anchoring device is characterized in that the anchoring device can be unfolded when the pressure in the main body cavity reaches the opening pressure condition of the anchoring device, so that the shale reservoir heating device keeps the underground position stable, meanwhile, the protective shell is kept in contact with the well wall, the electric charge is prevented from being retained by the protective shell, and the safety of equipment is ensured.

The protective casing is characterized in that the internal sealing performance of the shale reservoir downhole heating device can be maintained, and the safety of a main cable and other equipment is ensured.

The shale reservoir heating device based on oil pipe conveying is characterized by comprising 4 groups of lower pressing devices, an upper supporting frame, a lower supporting frame, a heating resistance plate, an external temperature and pressure sensor, an internal temperature and pressure sensor and an anchoring device, and the shale reservoir heating device is arranged on a protective shell around the axis of a main cable at an interval of 90 degrees.

By the method, the shale reservoir after hydraulic fracturing construction can be subjected to heat treatment modification. After the hydraulic fracturing construction, due to the fact that micro-nano-scale pores developed in the shale reservoir have strong self-absorption capacity, a large amount of water-based fracturing fluid is retained in the shale reservoir, and the retention amount of the fracturing fluid in a near-well zone of the shale gas well is extremely large. The temperature near the well periphery of the gas well is increased, the migration of the retained fracturing fluid in the near-well zone of the shale gas well can be promoted, and the damage of water phase trapping caused by early-stage hydraulic fracturing construction can be relieved.

The shale reservoir heating device based on oil pipe conveying provided by the invention has the following advantages:

(1) the process is simple and convenient, the application range is wide, and the construction can be completed through common underground operation measures. The shale reservoir heating device based on oil pipe delivery provided by the invention has no special requirements on a casing pipe in a well, and can be lowered to a preset position in the well by connecting the shale reservoir heating device based on oil pipe delivery with the oil pipe.

(2) The reservoir heating is achieved while preventing new damage from being created. CN108505971A proposes a process and an apparatus for heating a reservoir by injecting a hot fluid, but in combination with the actual situation of a shale reservoir, because the heat capacity of gas is low, the injection of high-temperature gas cannot achieve effective heating of the reservoir, and the injection of high-temperature liquid may cause the reservoir to suffer more serious damage, so the process and the apparatus for heating a reservoir by injecting a hot fluid proposed in CN108505971A cannot be used for heat treatment construction of a shale reservoir. The shale reservoir heating device based on oil pipe conveying provided by the invention is based on a resistance heating technology, adopts a contact heating process, and does not introduce new reservoir damage factors.

(3) The reservoir can be safely and stably heated. The reservoir heating device based on oil pipe conveying provided by the invention mainly provides energy for the reservoir in a resistance heating mode, and is matched with an internal temperature and pressure sensor and an external temperature and pressure sensor, so that underground construction parameters can be measured and controlled, and the reservoir can be stably heated. In addition, the heating process of the invention has no open fire or explosion process, and the safety of the reservoir and the underground equipment can be effectively protected.

Drawings

FIG. 1 is a schematic structural diagram of a reservoir heating device based on tubing conveyed according to the present invention;

FIG. 2 is a top view of a tubing conveyed reservoir heater according to the present invention;

shown in the figure:

the device comprises a main cable 1, a lower pressure device 2, an internal temperature and pressure sensor 3, an upper support frame 4, a flexible cable 5, a heating resistance plate 6, an external temperature and pressure sensor 7, a lower support frame 8, a protective shell 9, an anchoring device 10 and a main body cavity 11.

Detailed Description

The reservoir heating device based on tubing transportation provided by the invention is further explained with reference to the attached drawings.

Fig. 1 is a schematic structural diagram of a reservoir heating device based on tubing transportation according to the present invention. The main cable (1) is positioned in the center of the main body chamber (11), is mainly connected with a flexible cable (5), and supplies power to the heating resistance plate (6) through the flexible cable (5). Meanwhile, the internal temperature and pressure sensor (3) and the external temperature and pressure sensor (7) transmit data to the main cable (1) through the flexible cable (5) and transmit the data to the ground control equipment through the main cable (1). One end of the lower pressure device (2) is contacted with the main body cavity (11), the other end of the lower pressure device is hinged with the upper support frame (4), the heating resistance plate (6) is hinged together by the upper support frame (4) and the lower support frame (8), and the other end of the lower support frame (8) is hinged with the protective shell (9). When the internal pressure of the main body chamber (11) reaches a sufficient value, the lower pressure device (2) moves downwards under the action of the pressure, so that the upper support frame (4) and the lower support frame (8) move together, and the heating resistance plate (6) is enabled to be attached to the inner wall of the shaft. The anchoring device (10) has certain starting pressure, and after the reservoir heating device based on oil pipe conveying is lowered to a preset position through the coiled tubing, gas is injected into the coiled tubing, so that the pressure inside the main body cavity (11) is increased to the starting pressure of the anchoring device (10), and the anchoring device (10) is opened. The anchoring device (10) can timely transfer the charge on the protective casing (9) to the stratum to protect the safety of the device because the anchoring device is simultaneously connected with the inside of the shaft and the protective casing. After construction is finished, the lower pressure device (2) can be moved upwards through pressure relief, the upper support frame (4) and the lower support frame (8) are driven to withdraw the heating resistance plate (6), then the pipe column is lifted upwards to withdraw the anchoring device (10), and the reservoir heating device can be freely lifted or lowered.

Fig. 2 is a top view of a reservoir heating apparatus based on tubing conveyed according to the present invention. The reservoir heating device based on oil pipe conveying comprises 4 groups of depressors (2) with the same function, an internal temperature and pressure sensor (3), a flexible cable (5), a heating resistance plate (6), an external temperature and pressure sensor 6 and an anchoring device (10).

Although the present invention has been described with reference to the above embodiments, it should be understood that the present invention is not limited to the above embodiments, and those skilled in the art can make various changes and modifications without departing from the scope of the present invention.