WO2015058359A1

WO2015058359A1 - Drilling auxiliary system

Info

Publication number: WO2015058359A1
Application number: PCT/CN2013/085698
Authority: WO
Inventors: 韩尉善
Original assignee: 信远达石油服务有限公司
Priority date: 2013-10-22
Filing date: 2013-10-22
Publication date: 2015-04-30
Also published as: US20160265346A1

Abstract

A drilling auxiliary system for transmitting downhole electromagnetic data and/or detecting a casing, comprising an insulating device (17) arranged on a drill pipe (5) in the well for stopping all current or suppressing loss of part of the current. When used to transmit the electromagnetic data, the drilling auxiliary system can substantially reduce useless power consumption in the formation and effectively improve transmission efficiency of the downhole electromagnetic data, and when used to detect the casing, it can effectively increase the detection range of the casing.

Description

Drilling Auxiliary System Technical Field

Field of the Invention This invention relates to the field of oil drilling technology and, in particular, to a drilling assistance system that can be used for downhole data transmission and casing detection. Background technique

The Logging While Drilling of the oil industry generally refers to measuring the physical parameters of formation rocks during the drilling process, and uses the data telemetry system to send the measurement results to the ground for processing.

One of the key technologies of logging while drilling is signal transmission. Currently, drilling fluid pressure pulses (such as mud pulse) are widely used. This is a commonly used method for logging while drilling tools. It converts the measured parameters into The drilling fluid pressure pulse is circulated to the surface with the drilling fluid. The advantage of drilling fluid pressure pulse transmission is economical and convenient. The disadvantage is that the data transmission rate (the number of data bits transmitted per second) is low.

In recent years, in order to increase the transmission rate, the electromagnetic wave transmission technology has been tried. Figure 1 illustrates a typical downhole electromagnetic transmission system of the prior art. An insulating ring 2 is disposed on the drill pipe 5 above the drill bit 4 to divide the drill pipe into upper and lower sections which are insulated from each other, and the low-frequency power source 3 is loaded on the drill pipe sections at both ends of the insulating ring. As indicated by the arrows in the figure, the formation (referring to the formation from the vicinity of both ends of the insulating ring 2 to the infinity) forms a loop with the power source. The lines with arrows in the figure indicate the distribution of current in the formation. The thicker arrows indicate larger current intensities, the thinner arrows indicate smaller current intensities, and the dashed arrows indicate current intensities compared to the solids in solid arrows. More faint. The current at different times varies in amplitude and phase, but the ratio of the current intensities between them is substantially constant. Because the current is symmetrically distributed on both sides of the drill pipe and the casing (for asymmetric formations, such as large dip drilling, the distribution will change, but will not affect the conclusion, so it will not be discussed here). From the standpoint, Figure 1 only shows Current distribution on the left side of the drill pipe. As shown in Fig. 1, the current is stronger at the sub-circuit near the insulating ring 2, and the strength is smaller at the sub-circuit farther from the insulating ring 2, and when the well being drilled is deeper (for example, 2000 m or more) Well), through the sub-loop near the surface, the current is already very weak. The downhole data is loaded onto the power supply and transmitted to the surface by the electromagnetic field generated by the current. The ground end A of the casing of the well 1 being drilled is connected to a signal receiver 10, and the other end of the signal receiver 10 is connected to the infinity ground terminal B. Thus, by measuring the voltage change of the signal receiver 10, the downhole data can be obtained. Since the electromagnetic signal passing through the sub-loop near the surface is very small, it receives the signal The sensitivity of the device 10 is very high, and the data transmission rate is also very limited.

On the other hand, in the drilling process, it is often necessary to locate the downhole casing that already exists in the vicinity. There are currently two well-established downhole casing positioning techniques: one is to place a transmitting power source (or launching device) in an existing well, which generates an electromagnetic field in the formation and is drilling A receiving device is placed on the drill pipe of the well, which detects the electromagnetic field and determines the position of the existing well. This method detects a long distance, but the operation is complicated and the cost is high. Another technique is to place the transmitting power source (or transmitting device) and the receiving device on the drill pipe of the well being drilled. The transmitting power source (or transmitting device) generates an electromagnetic field in the formation that will exist in the existing well. An induced current is generated across the casing, which induces a secondary electromagnetic field in the formation that can be detected by the receiving device to determine the location of the existing well. The advantage of this method is that it is relatively simple, but the detection range is greatly reduced. Summary of the invention

It is an object of the present invention to overcome the deficiencies of the prior art and to provide an efficient solution for downhole electromagnetic data transmission and/or casing detection.

To achieve the above objects, the present invention provides a drilling assistance system for downhole electromagnetic data transmission and/or casing detection, the drilling assistance system including a drill pipe mounted on a well for blocking all current or suppressing large Insulation device with partial current loss.

Wherein the insulating means prevents or inhibits current flow between the drill pipe and the medium surrounding the drill pipe, or prevents or inhibits current flow between the drill pipe and the medium inside the drill pipe.

Wherein, the medium around the drill pipe includes a nearby formation, and the medium inside the drill pipe includes mud on the inner side of the drill pipe.

Wherein the insulating means surrounds the drill pipe, the insulating means is embedded in the drill pipe wall, or is mounted adjacent to the drill pipe, or is mounted at a position separate from the drill pipe.

Wherein the drill pipe is tubular, the insulating device comprises an inner insulating device and an outer insulating device, the inner insulating device surrounds an inner wall of the drill pipe, the inner insulating device is embedded in the inner wall of the drill pipe, or is mounted on the inner wall of the drill pipe The inner wall of the drill pipe is installed at a position separated from the inner wall of the drill pipe; the outer insulation device surrounds the outer wall of the drill pipe, and the outer insulation device is embedded in the outer wall of the drill pipe or is mounted on the outer wall of the drill pipe. Or installed at a position separate from the outer wall of the drill pipe.

Wherein the insulating device covers a transmitting and receiving instrument that is partially or fully mounted on the drill pipe.

Wherein, the insulating device performs a full 360 degree wrap around the drill pipe section enclosed; or The surrounding drill pipe section is partially surrounded by a non-360 degree.

Wherein, the insulating device is an insulating sheet of a specific shape, and blocks the current in a specific orientation.

Wherein, the shape of the insulating sheet is square, elliptical or any other shape.

Therein, one or more gaps are left on the insulating device, and the gap allows current to pass therethrough. Wherein, the gap on the insulating device can be any shape.

Wherein, the gap on the insulating device may be located at any position of the insulating device.

Wherein the gaps in the insulating means are used to control the direction and/or position of current flow or inflow.

Wherein, the insulating device encloses or partially encloses the insulating ring on the drill pipe, and partially or completely drills 4 dry segments extending from both sides of the insulating ring.

Wherein, the insulating device encloses or partially encloses the insulating ring and part or all of the drill pipe segments extending from one side of the insulating ring.

Wherein, the insulating device wraps part or all of the drill pipe segments extending from one side of the insulating ring. Compared with the prior art, the present invention has the following technical effects:

When the invention is applied to electromagnetic data transmission, the useless power consumption in the formation can be greatly reduced, thereby effectively improving the efficiency of underground electromagnetic data transmission.

When the invention is applied to the casing detection, the casing detection distance can be effectively increased. DRAWINGS

Figure 1 shows a typical downhole electromagnetic transmission system of the prior art;

Figure 2 shows a schematic diagram of current distribution of a drilling assistance system;

3 is a schematic view showing a downhole electromagnetic data transmission system according to an embodiment of the present invention; FIG. 4 is a schematic view showing a modification of a drilling assistance system according to an embodiment of the present invention;

Figure 5 is a schematic view showing a drilling assistance system of another embodiment of the present invention;

Figure 6 is a schematic view showing a drilling assistance system according to still another embodiment of the present invention;

Figure 7 is a schematic view showing a drilling assistance system according to still another embodiment of the present invention;

Figure 8 is a schematic view showing a drilling assistance system according to still another embodiment of the present invention;

Figure 9 is a schematic view showing a drilling assistance system according to still another embodiment of the present invention;

Figure 10 is a schematic view showing a drilling assistance system according to still another embodiment of the present invention;

Figure 11 shows one of the drilling assistance systems of the present invention which are suitable for connecting different branches of the same well. Schematic of one embodiment;

Figure 12 is a schematic illustration of another embodiment of a drilling assistance system suitable for use in connecting different branches of the same well;

Figure 13 shows a schematic view of yet another embodiment of the present invention adapted to connect different branches of the same well;

14a-f are schematic views showing the mounting of the insulating device to the drill pipe in a preferred embodiment of the present invention, wherein Fig. 14a shows a longitudinal sectional view of a drill pipe to which a surrounding insulating device is mounted, Figs. 14b~f respectively A transverse cross-sectional view of a drill pipe mounted with a surrounding insulating device based on AA in Figure 14a, section EE, section is shown. detailed description

The invention is further described below in conjunction with the drawings and specific embodiments.

Figure 3 shows a schematic diagram of a downhole electromagnetic data transmission system in accordance with one embodiment of the present invention. As in Figure 1, Figure 3 shows only the current distribution on one side of the drill pipe. Referring to Fig. 3, the downhole electromagnetic data transmission system of the present embodiment includes an insulating device 17 which is an insulating means for wrapping the drill pipe 5 360 degrees. It can be placed against the drill pipe 5, can be kept at a distance from the drill pipe 5, or can be embedded as a part of the drill pipe 5 during production. In the present embodiment, the insulating means 17 encloses the insulating ring 2 and the drill rods on both sides connected to the insulating ring 2. Because of the presence of the insulating device 17, current is prevented from flowing from the drill pipe to the nearby formation, making it impossible to form a circuit in the formation near the power source as in Fig. 1, thereby forcing the current to move along the drill pipe away from both ends of the power supply, thereby enhancing other regions. current intensity. Since the power loss in the formation near the power supply is exactly the largest, suppressing this part of the useless loss can greatly enhance the useful current intensity near the surface, thereby effectively increasing the efficiency of downhole data transmission.

In accordance with another embodiment of the present invention, a drilling assistance system is provided. The drilling assistance system is an improvement of the drilling assistance system involved in another patent application by the inventors. For ease of understanding, the first step is to introduce the drilling assistance system involved in another patent application. Figure 2 shows a schematic diagram of the current distribution of a drilling assistance system in accordance with another patent application. In this figure, in the well 1 being drilled, the drill pipe 5 is provided with an insulating ring 2 to divide the drill pipe into two upper and lower sections which are insulated from each other, and the upper and lower drill pipe sections are connected by the transmitting power source 3 (the transmitting power source 3 and the drill) The connection point of the rod segment is located near the ends of the insulating ring 2, as shown in Fig. 2). The wellhead end A of the casing 7 of the well being drilled 1 is connected by wire between the wellhead end B of the casing 8 of the already existing well 6, and the signal receiver 10 is connected in series with the wire. Thus by the launch power source 3, the drill pipe 5 of the well 1 being drilled, the casing of the well 1 being drilled 7 (the casing is usually a conductor), the wire between the two wells, the existing casing 8 of the well 6, and the formation between the two wells form a large loop that has less energy dissipation in the formation. Therefore, it can be used for efficient data transmission efficiency. Specifically, referring to FIG. 2, the current of the transmitting power source has two loops, the first loop is the current flowing from the upper end of the transmitting power source, through the drill pipe 5, the ground wire, the casing of the existing well, the ground layer, and then under the transmitting power source. The drill pipe section returns to the power source to form a loop; the second loop is the current flowing from the upper end of the launch power source, and the drill pipe section under the drill pipe, the ground layer, and the launch power source is returned to the power source to form a loop. Since the electrical energy in the first circuit is mainly consumed in the well below the existing well and the stratum between the drill pipe section (and the drill bit) under the power supply, and because the distance between the existing well and the well being drilled is not Far, so the current in this loop is large enough. Most of this current flows through the connection between the well being drilled and the known well, so the various measurements while drilling from the downhole launch power supply are easily received by the ground receiver to achieve the transmission signal. Since the current in the first loop is relatively strong, a relatively high frequency can be used, thereby increasing transmission efficiency. In Figure 2, the current flowing from the well being drilled through the formation to the existing well near the surface is small, so it is indicated by a lighter arrow.

Fig. 4 is a schematic view showing an improvement of the above-described drilling assistance system according to an embodiment of the present invention. The modification of this embodiment adds an insulating means 17 to the example of Fig. 2. As with the embodiment of Fig. 3, the insulating device 17 of this embodiment is a 360 degree surrounding insulating device. The surrounding insulation surrounds the insulating ring 2 and the upper and lower drill pipe sections of the drill pipe 5 adjacent to the insulating ring 2, respectively. The presence of the insulating device 17 suppresses the flow of current from the drill pipe to the nearby formation. The formation near the power supply cannot form a loop as in Figure 2, forcing the current to move along the drill pipe away from both ends of the power supply, thereby enhancing the rest of the entire large circuit. Area (for example) current intensity. Since the current on the cross-well connection AB is enhanced and this portion of the current can be used to transmit data, when the drilling assistance system of the present embodiment is used to transmit data, the data transmission efficiency can be effectively improved.

Figure 5 is a schematic illustration of a drilling assistance system of another embodiment of the present invention that enables efficient downhole electromagnetic data transmission. The difference between this embodiment and the embodiment of Fig. 4 is that: in this embodiment, the signal receiving device 10 is loaded on the inter-well line, so that the downhole data loaded on the low-frequency power source 3 can be received by the ground 10 . The remaining structure and current distribution of this embodiment are the same as those of the embodiment of FIG. 4, and details are not described herein again.

Figure 6 shows a schematic diagram of a drilling assistance system in accordance with yet another embodiment of the present invention that can perform high efficiency casing detection. The difference between this embodiment and the embodiment of FIG. 5 is that the signal receiving device 10 is not loaded on the inter-well line, and is not wrapped by the insulating device 17 above the insulating device 17. A casing detection receiver 11 is loaded on the drill pipe section. The remaining structure and current distribution of this embodiment are consistent with the embodiment of FIG. When current is delivered to an existing well, current flows down the casing of the existing well and flows through the formation to the drill pipe below the power source of the well being drilled, returning to the power supply. It is clear that a significant portion of the current will pass through the casing of the existing well back to the well being drilled. The casing detection receiver 11 on the drill pipe can detect the current on the casing 8 of the existing well 6 to generate an electromagnetic field to determine the distance and orientation of the existing well. This embodiment enhances the current on the casing 8 of the existing well 6 by adding the insulating means 17, so that when the drilling assist system of the present embodiment is used for casing detection, the casing detection distance can be effectively increased. Moreover, in the embodiment, under the premise of ensuring the effective detection distance, it is not necessary to stop the industrial production of the existing well, and no complicated instrument is added, so the detection cost is greatly reduced.

Figure 7 shows a schematic diagram of a drilling assistance system in accordance with yet another embodiment of the present invention that can perform high efficiency casing detection. The difference between this embodiment and the embodiment of Fig. 5 is that a casing detecting receiver 11 is added to the drill pipe section not covered by the insulating means 17 below the insulating means 17. The remaining structure and current distribution of this embodiment are the same as those of the embodiment of FIG. 5, and are not described herein again.

Figure 8 is a schematic illustration of a drilling assistance system in accordance with yet another embodiment of the present invention that can perform high efficiency casing detection. The difference between this embodiment and the embodiment of Fig. 6 is that the casing detecting receiver 11 is mounted at a different position. In this embodiment, the casing detecting receiver 11 is loaded on the drill pipe section wrapped in the insulating device 17. The remaining structure and current distribution of this embodiment are the same as those of the embodiment of Fig. 6, and are not described herein again.

Figure 9 is a schematic illustration of a drilling assistance system in accordance with yet another embodiment of the present invention that enables efficient data transmission and casing detection. The difference between this embodiment and the embodiment of Fig. 6 is that a signal receiving device is added to (or near) the inter-well connection. Furthermore, the system of the embodiment loads an auxiliary power source on the surface. The auxiliary power supply can increase the useful signal strength of the upward conduction while increasing the current intensity of the existing well casing, which can increase the data transmission rate and the extended casing detection effective distance. The remaining structure and current distribution of this embodiment are the same as those of the embodiment of Fig. 6, and will not be described herein.

Figure 10 is a schematic illustration of a drilling assistance system in accordance with yet another embodiment of the present invention that can perform efficient data transmission and casing detection simultaneously. The difference between this embodiment and the embodiment of Fig. 6 is that the surrounding insulating device 17 only surrounds a portion of the drill pipe section to which the end of the insulating ring is connected. The rest of the structure of the embodiment is the same as that of the embodiment of FIG. 9, and details are not described herein again.

Figure 11 illustrates an embodiment of the drilling assistance system of the present invention suitable for connecting different branches of the same well, which can perform efficient data transfer by connecting different branches of the same well. The system The working principle is the same as connecting wires between different wells. The signal receiving device 10 of the system can be placed on the line between the two branches, or placed on the ground, and connected from the ground to the line between the two branches by wires, as shown in FIG. In this embodiment, data transmission is achieved by measuring voltage changes at two branch connections and at infinity 9. In the figure, 15 is the branch of the existing well, 16 is the casing of the existing branch, 13 is the branch being drilled, and 14 is the casing of the branch being drilled.

Figure 12 illustrates another embodiment of the drilling assistance system of the present invention suitable for connecting different branches of the same well, which can be used to probe the existing branch by connecting different branches of the same well. The system is similar to the system shown in Fig. 11, except that the casing detecting device 11 is mounted on the drill pipe section above the insulating surrounding device on the branch being drilled, and the signal receiving device 10 is eliminated. The rest of the structure of this embodiment is the same as that of FIG. 11, and details are not described herein again.

Figure 13 illustrates yet another embodiment of the present invention that is adapted to connect different branches of the same well, which can simultaneously perform data transmission and casing detection by connecting different branches of the same well. The difference between this embodiment and the embodiment of Fig. 11 is that a casing detecting device is installed on the drill pipe section above the insulating surrounding device on the branch being drilled, and the rest of the structure is identical to that of Fig. 11 and will not be described herein.

Figures 14a-f show schematic views of an insulating device mounted to a drill pipe in a preferred embodiment of the invention. Figure 14a shows a longitudinal section through a drill pipe 5 with a circumferential insulating device 17 mounted, and Figure 14b shows a transverse sectional view of the drill pipe 5 with a surrounding insulating device 17 mounted based on AA in Figure 14a. Figure 14c shows a transverse cross-sectional view of the drill pipe 5 with the surrounding insulating device 17 mounted on the basis of BB in Figure 14a, and Figure 14d shows the circumferentially mounted insulating device 17 based on CC in Figure 14a. A transverse cross-sectional view of the drill pipe 5, Figure 14e shows a transverse cross-sectional view of the drill pipe 5 with the surrounding insulating device 17 mounted based on the DD of Figure 14a, and Figure 14f shows the profile based on EE in Figure 14a. A transverse cross-sectional view of the drill rod 5 with the surrounding insulating means 17 mounted. As shown in Figures 14a-f, the drill pipe 5 in this embodiment is a hollow tubular drill pipe. The insulating device 17 includes an outer insulating device 18 mounted on the outside of the drill pipe and an inner insulating device 19 mounted on the inner side of the drill pipe. It should be noted that in other embodiments, the outer insulating device 18 and the inner insulating device 19 may also be used separately. When used alone, the outer insulating device 18 or the inner insulating device 19 can also suppress the current from the drill pipe 5 into the mud of the nearby formation or the inside of the drill pipe to a certain extent, thereby also improving the data transmission efficiency to some extent and/or Improve the efficiency of casing detection.

In the foregoing embodiments of Figures 3 to 13, for the convenience of drawing, only the insulating means on the outside of the drill pipe are drawn, and in fact, they can each have an inner insulating means inside the drill pipe, which is easily understood by those skilled in the art.

In addition, the insulating device can 360-degree full wrap around the wrapped drill pipe section, or only The wrapped drill pipe section is partially surrounded by a non-360 degree. One or more voids may be left on the insulating device and allow current to pass. The voids on the insulating device can be of any shape. The gaps in the insulating device can be anywhere in the insulating device. The gaps in the insulating device can be used to control the direction and position of current flow or inflow. This is easily understood by those skilled in the art.

The insulating means may also be an insulating sheet of a particular shape to block the current in a particular orientation. The shape of the insulating sheet may be a regular shape such as a square shape, an elliptical shape or the like, or may be an irregular shape, which is easily understood by those skilled in the art.

Finally, it should be noted that the above embodiments are only used to describe the technical solutions of the present invention and are not intended to limit the technical methods. The present invention may be extended to other modifications, changes, applications, and embodiments, and thus all such Modifications, variations, applications, and embodiments are within the spirit and scope of the invention.

Claims

Rights request

I. A drilling auxiliary system for downhole electromagnetic data transmission and/or casing detection. The drilling auxiliary system includes an insulation device installed on the drill pipe of the well to block all current or suppress partial current loss.

2. The drilling auxiliary system according to claim 1, characterized in that the insulation device prevents or inhibits the flow of current between the drill pipe and the medium around the drill pipe, or prevents or inhibits the flow of current between the drill pipe and the inside of the drill pipe. flow between media.

3. The drilling auxiliary system according to claim 2, wherein the medium around the drill pipe includes the formation near the drill pipe, and the medium inside the drill pipe includes mud inside the drill pipe.

4. The drilling auxiliary system according to claim 3, characterized in that, the insulation device surrounds the drill pipe, the insulation device is embedded in the drill pipe wall, or is installed close to the drill pipe, or is installed with the drill pipe. where the rods separate.

5. The drilling auxiliary system according to claim 3, characterized in that, the drill pipe is tubular, the insulation device includes an inner insulation device and an outer insulation device, the inner insulation device surrounds the inner wall of the drill pipe, so The inner insulation device is embedded in the inner wall of the drill pipe, or is installed close to the inner wall of the drill pipe, or is installed at a position separated from the inner wall of the drill pipe; the outer insulation device surrounds the outer wall of the drill pipe, and the outer insulation device is embedded in the inner wall of the drill pipe. On the outer wall of the drill pipe, or installed close to the outer wall of the drill pipe, or installed at a position separated from the outer wall of the drill pipe.

6. The drilling auxiliary system according to claim 3, characterized in that the insulation device covers part or all of the transmitting and receiving instruments installed on the drill pipe.

7. The drilling auxiliary system according to claim 3, characterized in that the insulation device performs a 360-degree full surround of the surrounded drill pipe section; or performs a non-360-degree partial surround of the surrounded drill pipe section.

8. The drilling auxiliary system according to claim 3, characterized in that the insulation device is an insulating sheet of a specific shape, which blocks the current in a specific direction.

9. The drilling auxiliary system according to claim 8, characterized in that the shape of the insulation sheet is square, oval or any other shape.

10. The drilling auxiliary system according to claim 7 or 8, characterized in that one or more gaps are left on the insulation device, and the gaps allow current to pass.

II. The drilling assistance system according to claim 10, characterized in that the gaps on the insulation device can be of any shape.

12. The drilling auxiliary system according to claim 10, characterized in that the gap on the insulation device can be located at any position of the insulation device.

13. The drilling auxiliary system according to claim 10, characterized in that the gap on the insulation device is used to control the direction and/or position of current outflow or inflow.

14. The drilling auxiliary system according to claim 7, characterized in that the insulating device wraps or partially wraps an insulating ring on the drill pipe, and part or all of the drill pipe segments extending in both directions from the insulating ring.

15. The drilling auxiliary system according to claim 7, characterized in that the insulation device wraps or partially wraps the insulating ring and part or all of the drill pipe section extending in one direction from the insulating ring.

16. The drilling auxiliary system according to claim 7, characterized in that the insulation device wraps part or all of the drill pipe section extending in one direction from the insulation ring.