A device and method for hydraulic pressure measurement while drilling

Abstract

The application provides a device and method for hydraulic pressure measurement while drilling, and belongs to the technical field of drilling water gushing pressure measurement. The device comprises an inlet and outlet port allowing fluid to enter and exit, a flow test chamber connected with the inlet and outlet port, a sealing measurement unit for sealing the inlet and outlet port and measuring the drilling water gushing pressure, a packer for closing the drilling, a hydraulic control unit for controlling the packer to close or open the drilling, a piston and a pushing ring. The application can measure the drilling water gushing pressure and fluid flow at different positions in real time by controlling the closing or opening of the drilling in real time, and the redundant actions of pulling out the drill and replacing the drill collar are omitted, so that the work efficiency is greatly improved.

Description

Technical Field

[0001] This invention relates to the field of borehole water pressure measurement technology, and particularly to an apparatus and method for measuring water pressure while drilling. Background Technology

[0002] The statements in this section are merely background information related to the present invention and do not necessarily constitute prior art.

[0003] The borehole inrush pressure in tunnels refers to the pressure of pressurized water entering the borehole when encountering a confined aquifer during drilling. The detection and prediction of borehole inrush pressure are crucial for ensuring safe drilling, improving drilling efficiency, optimizing drilling processes, and reducing drilling costs. In the field of borehole prediction, predicting aquifers ahead is extremely important. Although geophysical exploration methods are very convenient, their ambiguity and inability to provide fully quantitative data cannot accurately provide predictive data. Therefore, by combining drilling operations with monitoring borehole inrush pressure, the conditions of aquifer areas ahead can be accurately predicted and assessed. This allows for early detection of groundwater development in aquifers ahead of the tunnel face, enabling proactive measures to be taken to avoid disasters such as water and mud inrushes.

[0004] The inventors discovered that tunnel drilling operations are often horizontal or at small angles, and the traditional formulas and methods for calculating borehole water pressure in traditional vertical shafts are not suitable for tunnel drilling operations. Moreover, traditional oil and gas well borehole water pressure measurement equipment is expensive and has a low cost-effectiveness for tunnel drilling operations with shallow depths. In addition, current methods for measuring borehole water pressure often require raising the drill string, changing equipment, and then lowering the drill string again for measurement, which greatly affects drilling efficiency for tunnel drilling operations with fast progress and short operation times. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides an apparatus and method for measuring borehole water pressure while drilling, which can measure borehole water pressure more conveniently and accurately, and eliminates the steps of lifting the drill bit and changing the drill collar in traditional measurement methods, thus greatly improving work efficiency.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] In a first aspect, the present invention provides an apparatus for measuring hydraulic pressure while drilling.

[0008] A device for measuring hydraulic pressure while drilling includes at least: a sealing measurement assembly, a packer, and a fluid test chamber disposed within the body of a drill collar, the fluid test chamber being connected to a water inlet at the front of the drill collar and a water outlet at the rear of the drill collar;

[0009] The sealing measurement assembly includes: a first sealing block, a first drive rod, a second sealing block, a second drive rod, a probe, a flow meter probe, and an integrated control unit. The flow meter probe is located outside the drill collar and connected to the integrated control unit. The probe is located in the fluid test chamber and connected to the integrated control unit.

[0010] The first sealing block is connected to the first driving rod and is used to seal or open the water inlet under the action of the first driving rod. The second sealing block is connected to the second driving rod and is used to seal or open the water outlet under the action of the second driving rod.

[0011] The packer is located between the inlet and outlet of the drill collar and is used to close or open the borehole under the control of the first drive mechanism.

[0012] As a further limitation of the first aspect of the present invention, the first driving mechanism includes a push ring, a piston, and a hydraulic control unit. The push ring is located at the rear of the packer, and the piston is located at the rear of the push ring. The push ring is used to control the packer to close or open the borehole under the drive of the piston.

[0013] As a further limitation of the first aspect of the present invention, the first drive rod is connected to the second drive mechanism, the second drive rod is connected to the second drive mechanism, and a hydraulic balance through hole is provided in the piston and the drill collar body. The first drive mechanism is a hydraulic drive mechanism, a pneumatic drive system, or an electric cylinder drive mechanism, and the second drive mechanism is a hydraulic drive mechanism.

[0014] As a further limitation of the first aspect of the present invention, the propulsion ring is connected to a limiter so that the propulsion ring does not block the outlet when the packer is closed or opened. The first sealing block, the first drive rod, the second sealing block, the second drive rod, the probe, the flow meter probe, the propulsion ring, the limiter, the piston and the drill collar body are all made of metal.

[0015] As a further limitation of the first aspect of the present invention, the fluid test chamber is provided with a first sealing gasket for cooperating with the first sealing block near the water inlet, and a second sealing gasket for cooperating with the second sealing block is provided near the water outlet of the fluid test chamber.

[0016] As a further limitation of the first aspect of the present invention, the propulsion ring is provided with an opening at a position for coinciding with the water outlet to cooperate with the water outlet.

[0017] Secondly, the present invention provides a method for operating a device for measuring hydraulic pressure while drilling.

[0018] A method for operating an apparatus for measuring hydraulic pressure while drilling, utilizing the apparatus for measuring hydraulic pressure while drilling as described in the first aspect of the present invention, includes the following steps:

[0019] Before drilling begins, the inlet is sealed with the first sealing block and the outlet is sealed with the second sealing block.

[0020] When drilling is underway, if the flow rate data collected by the flow meter probe at a certain point exceeds the predetermined value, it is determined that there is a water inrush point at that point, and the measurement operation begins.

[0021] The hydraulic control unit controls the movement of the piston, which pushes the push ring to open the packer, thus completing the sealing action of the borehole;

[0022] The integrated control unit controls the first drive rod to retract the first sealing block to release the seal on the inlet, and then the fluid enters the flow measurement chamber;

[0023] The probe measures the borehole water pressure data. After the pressure data collection reaches the preset value, the integrated control unit controls the second drive rod to retract the second sealing block and release the seal of the water outlet.

[0024] The integrated control unit controls the probe to stop measuring borehole water inflow pressure data and start measuring flow rate data;

[0025] After data collection is complete, the hydraulic control unit controls the piston to move, and the piston pushes the push ring to close the packer, releasing the sealing action on the borehole;

[0026] The integrated control unit controls the first and second drive rods, which seal the inlet through the first sealing block and the outlet through the second sealing block.

[0027] As a further limitation of the second aspect of the present invention, during drilling operations, when the flow data collected by the flow meter probe exceeds a predetermined value, the integrated control unit determines that there is a water inrush point and sends a pulse signal to the face controller. The face control terminal receives the signal, records the water inrush location, and sends a pulse signal to the hydraulic control unit, and the measurement operation begins.

[0028] As a further limitation of the second aspect of the present invention, when there are multiple water inflow points in the borehole, when a water inflow point is encountered during the drilling process, the measurement work is completed and the water inflow location and related flow data are recorded before drilling continues. This process is repeated for subsequent water inflow points until the drilling task is terminated.

[0029] When there are multiple water inflow points in the borehole, before lifting the drill bit after drilling ends, the water inflow points are re-measured. The water inflow point data measured during drilling represents the water volume and water pressure at the time of drilling. The water inflow point data re-measured when lifting the drill bit represents the total water pressure and total water volume of the water inflow section before the re-measured point. The initial drilling measurement data is corrected based on the data of the re-measured water inflow points.

[0030] When there are multiple water inflow points in the borehole, when the drill is pulled up after drilling ends, the face continuously receives pulse signals of the water inflow points. Based on the received pulse signals, it is determined whether it is a re-measurement point. If it is a re-measurement point, measurement work is carried out. After the measurement work is completed, the drill is pulled up again; if it is not a re-measurement point, the drill is pulled up again.

[0031] Thirdly, the present invention provides a drill collar, characterized in that it includes the device for measuring hydraulic pressure while drilling as described in the first aspect of the present invention.

[0032] Compared with the prior art, the beneficial effects of the present invention are:

[0033] 1. This invention innovatively proposes a device for measuring hydraulic pressure while drilling. Data can be uploaded in real time through a sealed measurement unit, and the opening and closing of the packer can be controlled in real time through a hydraulic control unit. This facilitates data extraction and eliminates the step of lifting the drill string to replace the drill collar, thereby improving measurement efficiency.

[0034] 2. This invention innovatively proposes a device for measuring water pressure while drilling. By integrating a pressure sensor and a flow sensor in the probe of the sealed measurement unit, flow data can be acquired while measuring water pressure while drilling.

[0035] 3. This invention innovatively proposes a device for measuring water pressure while drilling. Due to the presence of the packer, the borehole can be sealed at different water inflow points, thereby measuring the borehole water pressure at different locations. The test location is relatively flexible and one or more water inflow points can be measured during a single drilling process.

[0036] 4. This invention innovatively proposes a device for measuring hydraulic pressure while drilling. The measurement method is simple and reliable, has good adaptability to the characteristics of tunnel drilling operations, and is less expensive than oil and gas well measurement equipment. Attached Figure Description

[0037] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0038] Figure 1 This is a top-view structural schematic diagram of the drilling hydraulic pressure measurement device;

[0039] Figure 2 For drilling hydraulic pressure measurement device Figure 1 A schematic diagram of the cross-section at point AA;

[0040] Figure 3 This is a schematic diagram of the drilling process using a hydraulic pressure measurement and control (HPMR) device.

[0041] Figure 4 This is a flowchart illustrating the measurement process of the drilling hydraulic pressure measurement device.

[0042] Figure 5 Schematic diagram of drilling and re-measurement points under multiple water inflow points.

[0043] Figure 6 A flowchart illustrating the drilling measurement and re-measurement process under multiple water inflow points;

[0044] The components are as follows: 1. Inlet; 2. First sealing gasket; 3. First sealing block; 4. First hydraulic rod; 5. Sealing measurement unit; 6. Probe; 7. Fluid measurement chamber; 8. Flow meter channel; 9. Flow meter probe; 10. Packer; 11. Outlet; 12. Limiter; 13. Propulsion ring; 14. Hydraulic balance through hole; 15. Piston; 16. Hydraulic control unit; 17. Drill collar body; 18. Second sealing block; 19. Second hydraulic rod; 20. Second sealing gasket. Detailed Implementation

[0045] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0046] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0047] Where there is no conflict, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0048] Example 1:

[0049] like Figure 1 , Figure 2 , Figure 3 and Figure 4 As shown, Embodiment 1 of the present invention provides a device for measuring hydraulic pressure while drilling, comprising: an inlet 1 and an outlet 11 disposed on the outer sides of the front and rear parts of the drill collar body 17, the two being connected to the flow measurement chamber 7 through a connecting channel with a first sealing gasket 2 and a second sealing gasket 20.

[0050] In this embodiment, the sealing measurement unit 5 includes a first sealing block 3, a first hydraulic rod 4, a second sealing block 19, a second hydraulic rod 18, a probe 6, a flow meter probe 9, and an integrated control unit.

[0051] In this embodiment, the integrated control unit is directly connected to the probe 6 and connected to the flow meter probe 9 through the flow meter channel 8. The integrated control unit controls the action of the first hydraulic rod 4 and the second hydraulic rod 18 by controlling the second drive mechanism (preferably a hydraulic drive mechanism in this embodiment, but it can also be a pneumatic drive mechanism or an electric drive mechanism). The first hydraulic rod 4 (i.e. the first drive rod) is connected to the first sealing block 3, and the second hydraulic rod 18 (i.e. the second drive rod) is connected to the second sealing block 19.

[0052] In this embodiment, the probe 6 in the sealed measurement unit 5 is connected to the flow measurement chamber 7, and the pressure sensor and flow sensor are integrated inside.

[0053] In this embodiment, the flow meter probe 9 in the sealing measurement unit 5 is responsible for collecting flow data during drilling so as to transmit a measurement start signal.

[0054] In this embodiment, the packer 10 is located between the inlet 1 and the outlet 11 on the outside of the drill collar body. The push ring 13 is located at the rear of the packer 10, and the piston 15 is located at the rear of the push ring 13. The packer 10 is controlled to open and close by the hydraulic control unit 16 through the piston 15 and the push ring 13 with limiter 12. The piston 15 and the drill collar body 17 are provided with hydraulic balance through holes 14. The piston 15, the push ring 13 and the hydraulic control unit 16 form the first drive mechanism.

[0055] In this embodiment, the sealing block 3, hydraulic rod 4, probe 6, flow meter probe 9, propulsion ring 13, limiter 12, piston 15, and drill collar body 17 are all made of metal.

[0056] In this embodiment, the integrated control unit controls the extension and retraction of the first hydraulic rod 4 and the second hydraulic rod 19, thereby causing the first sealing block 3 and the second sealing block 19 to seal or unseal the connection channel. When sealing, the first sealing block 3 fits into the first sealing gasket 2, and the second sealing block 19 fits into the second sealing gasket 20, which can prevent foreign objects from entering during drilling.

[0057] In this embodiment, the first sealing block 3, the first sealing gasket 2, the second sealing block 19, and the second sealing gasket 20 are all made of rubber. The size of the first sealing block 3 matches the size of the first sealing gasket 2, and the size of the second sealing block 19 matches the size of the second sealing gasket 20.

[0058] In this embodiment, the hydraulic control unit 16 controls the piston 15 and the push ring 13 with limiter 12 to control the packer 10 to close or open the borehole by hydraulic means; the push ring 13 has an opening at the point where it overlaps with the outlet to prevent the outlet from being blocked, and the limiter 12 can ensure that the position of the push ring remains unchanged when drilling or opening the packer, thereby preventing the outlet from being blocked.

[0059] In this embodiment, the hydraulic control unit 16 is located inside the rear side of the drill collar 17 body.

[0060] Example 2

[0061] Embodiment 2 of the present invention provides a measurement method for a device for measuring hydraulic pressure while drilling, as described in Embodiment 1, comprising the following steps:

[0062] S1: Before drilling operations begin, ensure that the sealing blocks seal the inlet and outlet water ports;

[0063] S2: Drilling operation is carried out. When the flow data collected by the flow meter probe 9 exceeds the predetermined value, the integrated control unit determines that there is a water inrush point and sends a pulse signal to the face controller. The face controller receives the signal, records the water inrush location, and manually controls the transmission of a pulse signal to the hydraulic control unit, and the measurement operation begins.

[0064] S3: The hydraulic control unit 16 receives and decodes pulse signals, and adjusts the pressure of the gap between the piston 15 and the front and rear to hydraulically push the propulsion ring 13 to open the packer 10, thus completing the sealing action of the borehole.

[0065] S4: After completing the previous action, the hydraulic control unit 16 sends a pulse signal to the integrated control unit. After receiving and decoding the signal, the integrated control unit drives the front hydraulic rod 4 to retract the front sealing block 3 to release the seal on the inlet. Then the fluid enters the flow measurement chamber.

[0066] S5: Probe 6 continuously measures the borehole water pressure data and transmits it back to the ground in real time by the integrated control unit;

[0067] S6: After the pressure data collection reaches the preset value, the integrated control unit hydraulically drives the rear hydraulic rod 4 to retract the sealing block 3 and release the seal of the outlet.

[0068] S7: The integrated control unit controls probe 6 to stop measuring borehole water pressure data and start measuring flow data. The flow data is transmitted back to the ground through the integrated control unit.

[0069] S8: Data collection is complete, and a pulse signal to stop measurement is sent from the ground.

[0070] S9: The hydraulic control unit 16 receives and decodes the pulse signal, and the pressure in the gap between the front and rear of the balance piston 15 releases the packer 8 from the hole.

[0071] S10: After the hydraulic control unit 16 completes the previous action, the itemized control unit 5 sends a pulse signal, and the integrated control unit controls the hydraulic rods 4 on both the front and rear sides to push the sealing block 3 to seal the inlet and outlet.

[0072] In this embodiment, when there are multiple water inflow points in the borehole, when a water inflow point is encountered during drilling, the measurement work is completed and the water inflow location and related parameters are recorded before drilling continues. This process is repeated for subsequent water inflow points until the drilling task is terminated.

[0073] When there are multiple water inflow points in the borehole, before lifting the drill bit at the end of drilling, the water inflow points should be re-measured. Considering the representativeness of the water inflow points, three water inflow points are generally selected as re-measurement points: the water inflow point closest to the center of the first half of the water inflow point distribution section, the water inflow point in the center of the water inflow point distribution section, and the initial water inflow point. When the water inflow section is long and there are many water inflow points, the number of re-measurement points can be increased appropriately. It should be noted that the above three re-measurement points are necessary in the case of multiple water inflow points to determine whether the water inflow points in the water inflow point distribution section of the borehole are connected.

[0074] The data of the water inflow point measured during drilling represents the water volume and water pressure at the time of drilling. The data of the re-measured point when the drill is pulled up represents the total water pressure and total water volume of the water inflow section before the re-measured point. The re-measured data can correct the initial measurement data during drilling and also facilitate the understanding of the overall water inflow data of the borehole.

[0075] When there are multiple water inflow points in the borehole, when the drill is pulled up after drilling ends, the face continuously receives pulse signals of the water inflow points. The location is compared to see if it is a re-measurement point. If it is a re-measurement point, the measurement work is carried out. After the measurement work is completed, the drill is pulled up again. If it is not a re-measurement point, the drill is pulled up again.

[0076] by Figure 5 For example, during the drilling process, the first water inrush point A1 is encountered. The location is recorded and the water inrush data is measured before drilling continues. During the subsequent drilling process, the water inrush point A2 is encountered. The location is recorded and the water inrush data is measured before drilling continues. Until the target footage is reached, a total of 9 water inrush points are encountered, namely A1, A2, A3, A4, A5, A6, A7, A8, and A9 in the figure.

[0077] Based on the above selection criteria for retesting points, A7, A5, and A1 were selected as retesting points, and denoted as S1, S2, and S3, respectively. During the drilling process, the position of the drilling device was compared with the position of the retesting points. When the drill reached the retesting point, the retesting was performed. After the retesting was completed, drilling continued.

[0078] Considering the continuous water inflow at the water inflow point during drilling and hoisting, the water pressure and flow rate at point S1 were re-measured, with a flow rate of SUM. S1 for:

[0079] Water volume (SUM) S1 ≈A7+A8+A9;

[0080] Water pressure and flow rate at retest point S2, water flow rate SUM S2 for:

[0081] SUM S2≈A5+A6+A7+A8+A9;

[0082] Water pressure and flow rate at retest point S3, water flow rate SUM S3 for:

[0083] SUM S3 ≈A1+A2+A3+A4+A5+A6+A7+A8+A9;

[0084] Through water pressure and water volume SUM S1 SUM S2 SUM S3 It can provide data on the overall water pressure and volume of water in different water inflow sections.

[0085] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A device for measuring hydraulic pressure while drilling, characterized in that, At least including: The sealing measurement assembly, packer, and fluid test chamber are located inside the drill collar body. The fluid test chamber is connected to the water inlet at the front of the drill collar and to the water outlet at the rear of the drill collar. The flow meter probe in the sealing measurement unit is responsible for collecting flow data during drilling in order to transmit a measurement start signal; the packer is controlled to open and close by the hydraulic control unit through the piston and the push ring with limiters; the hydraulic control unit controls the piston and the push ring with limiters to control the packer to close or open the borehole by hydraulic means; The sealing measurement assembly includes: a first sealing block, a first drive rod, a second sealing block, a second drive rod, a probe, a flow meter probe, and an integrated control unit. The flow meter probe is located outside the drill collar and connected to the integrated control unit. The probe is located in the fluid test chamber and connected to the integrated control unit. The first sealing block is connected to the first driving rod and is used to seal or open the water inlet under the action of the first driving rod. The second sealing block is connected to the second driving rod and is used to seal or open the water outlet under the action of the second driving rod. The first drive mechanism includes a push ring, a piston, and a hydraulic control unit. The push ring is located at the rear of the packer, and the piston is located at the rear of the push ring. The push ring is used to control the packer to close or open the borehole under the drive of the piston. The packer is located between the inlet and outlet of the drill collar outside the drill collar. The packer is used to close or open the borehole under the control of the first drive mechanism. Because of the packer, the borehole can be sealed at different water inflow points, thereby measuring the borehole water pressure at different locations. The test location is flexible and one or more water inflow points can be measured during a single drilling operation.

2. The apparatus for measuring hydraulic pressure while drilling as described in claim 1, characterized in that, The first drive rod is connected to the second drive mechanism, and the second drive rod is connected to the second drive mechanism. A hydraulic balance through hole is provided in the piston and the drill collar body. The first drive mechanism is a hydraulic drive mechanism, a pneumatic drive system, or an electric cylinder drive mechanism; the second drive mechanism is a hydraulic drive mechanism.

3. The apparatus for measuring hydraulic pressure while drilling as described in claim 1, characterized in that, The push ring is connected to a limiter so that the push ring does not block the outlet when the packer is closed or opened. The first sealing block, the first drive rod, the second sealing block, the second drive rod, the probe, the flow meter probe, the push ring, the limiter, the piston, and the drill collar body are all made of metal.

4. The apparatus for measuring hydraulic pressure while drilling as described in claim 1, characterized in that, The fluid test chamber is provided with a first sealing gasket near the inlet for cooperating with the first sealing block, and a second sealing gasket is provided near the outlet for cooperating with the second sealing block.

5. The apparatus for measuring hydraulic pressure while drilling as described in claim 1, characterized in that, The propulsion ring has an opening at a position that coincides with the outlet to mate with the outlet.

6. A method for operating a device for measuring hydraulic pressure while drilling, characterized in that, The apparatus for measuring hydraulic pressure while drilling according to any one of claims 1-5 includes the following process: Before drilling begins, the inlet is sealed with the first sealing block and the outlet is sealed with the second sealing block. When drilling is underway, if the flow rate data collected by the flow meter probe at a certain point exceeds the predetermined value, it is determined that there is a water inrush point at that point, and the measurement operation begins. The hydraulic control unit controls the movement of the piston, which pushes the push ring to open the packer, thus completing the sealing action of the borehole; The integrated control unit controls the first drive rod to retract the first sealing block to release the seal on the inlet, and then the fluid enters the flow measurement chamber; The probe measures the borehole water pressure data. After the pressure data collection reaches the preset value, the integrated control unit controls the second drive rod to retract the second sealing block and release the seal of the water outlet. The integrated control unit controls the probe to stop measuring borehole water inflow pressure data and start measuring flow rate data; After data collection is complete, the hydraulic control unit controls the piston to move, and the piston pushes the push ring to close the packer, releasing the sealing action on the borehole; The integrated control unit controls the first and second drive rods, which seal the inlet through the first sealing block and the outlet through the second sealing block.

7. The operating method of the device for measuring hydraulic pressure while drilling as described in claim 6, characterized in that, During drilling operations, when the flow rate data collected by the flow meter probe exceeds the predetermined value, the integrated control unit determines that there is a water inrush point and sends a pulse signal to the face controller. The face control terminal receives the signal, records the water inrush location, and sends a pulse signal to the hydraulic control unit, thus initiating the measurement operation.

8. The operating method of the device for measuring hydraulic pressure while drilling as described in claim 6, characterized in that, When there are multiple water inflow points in the borehole, if a water inflow point is encountered during drilling, the measurement work is completed and the water inflow location and related flow data are recorded before drilling continues. This process is repeated for subsequent water inflow points until the drilling task is terminated. When there are multiple water inflow points in the borehole, before lifting the drill bit after drilling ends, the water inflow points are re-measured. The water inflow point data measured during drilling represents the water volume and water pressure at the time of drilling. The water inflow point data re-measured when lifting the drill bit represents the total water pressure and total water volume of the water inflow section before the re-measured point. The initial drilling measurement data is corrected based on the data of the re-measured water inflow points. When there are multiple water inflow points in the borehole, when the drill is pulled up after drilling ends, the face continuously receives pulse signals of the water inflow points. Based on the received pulse signals, it is determined whether it is a re-measurement point. If it is a re-measurement point, measurement work is carried out. After the measurement work is completed, the drill is pulled up again; if it is not a re-measurement point, the drill is pulled up again.

9. A drill collar, characterized in that, Includes the apparatus for measuring hydraulic pressure while drilling as described in any one of claims 1-5.

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