Patent Publication Number: US-2018051550-A1

Title: Measurement-while-drilling device and method

Description:
TECHNICAL FIELD 
     The embodiment of the present invention relates to a measurement device and a corresponding measuring method, and in particular, to a measurement-while-drilling device and a measuring method suitable for a drill apparatus. 
     BACKGROUND 
     The term “measurement-while-drilling” means that a drill machine, when it is drilling, collects continually the information about the drill well or a drill bit, such as an azimuth angle, stress, bit pressure, operation conditions of the drill bit, and the subsurface environment, and then the information is transmitted back to a control end so as to act as the basis of producing a control signal. Accordingly, the measurement-while-drilling device is the key to implement the technology of rotation drilling. 
     Most of measurement-while-drilling devices are disposed in a drill collar, and their core components are various sensors disposed therein. Because the subsurface environment presents complex and harsh extremely, the sealing of the housing of a measurement-while-drilling device becomes very important. A well-sealed housing is capable of protecting the sensors from the invasion of drilling liquids, sands, or the like, thereby improving the accuracy of the measurement of the sensors and prolonging the life of the sensors. As shown in  FIG. 1 , in the prior art, an axial groove  11  is provided at a cylindrical peripheral side surface  14  of a measurement-while-drilling device  10 , and after the sensor  12  has been installed therein, a cover  13  is provided on the groove to serve for sealing. By the measurement-while-drilling device of this design, it is convenient for the installation and maintenance of the sensor  12 . However, the design is of a complex structure, and the sealing effect and accuracy cannot be guaranteed 
     Accordingly, it is necessary to provide a measurement-while-drilling device adaptable for a drill apparatus, and a corresponding method of producing the same, so as to solve the above-mentioned technical problems. 
     SUMMARY 
     In light of the aforementioned technical problems, one aspect of the present invention is to provide a measurement-while-drilling device, comprising a base having a rotation axis and configured to be axially connected between a drill pipe and a drill bit of a drill apparatus. The base has a first and second end surfaces at the two axial ends thereof respectively and a cylindrical peripheral side surface extending between the first and second end surfaces. The base defines at least one sensing chamber which has an opening at at least one of the end surfaces. The base further includes a passage which is configured to allow liquid communication between the drill pipe and the drill bit. The measurement-while-drilling device further comprises at least one sensor disposed within the sensing chamber, and the sensor and the sensing chamber are configured to obtain drilling data and transmit the drilling data to a drilling control unit. The measurement-while-drilling device further comprises a sealing member configured to seal the sensing chamber on the at least one of the end surfaces. 
     Another aspect of the present invention is to provide a method, comprising: designing a predetermined drilling trajectory which leads to hydrocarbon to be produced; drilling a well bore with a drill apparatus comprising a measurement-while-drilling device based on the predetermined drilling trajectory; removing the drill apparatus from the well bore; and obtaining the hydrocarbon from the well bore. The step of drilling a well bore with a drill apparatus comprising a measurement-while-drilling device, comprises: obtaining drilling data with the measurement-while-drilling device, transmitting the drilling data to a drilling control unit, and calibrating a drilling direction of the drill apparatus based on the drilling data and the predetermined drilling trajectory. The measurement-while-drilling device comprises a base having a rotation axis configured to be axially connected between a drill pipe and a drill bit of the drill apparatus. The base has a first and second end surfaces at the two axial ends thereof respectively and a cylindrical peripheral side surface extending between the first and second end surfaces. The base defines at least one sensing chamber which has an opening at at least one of the end surfaces. The base further includes a passage which is configured to allow liquid communication between the drill pipe and the drill bit. The measurement-while-drilling device further comprises at least one sensor disposed within the sensing chamber. The measurement-while-drilling device further comprises a sealing member configured to seal the sensing chamber on the at least one of the end surfaces. 
     Another aspect of the present invention is to provide a method for producing a measurement-while-drilling device, comprising: providing a base having a rotation axis, configured to be axially connected between a drill pipe and a drill bit of a drill apparatus and having a first and second end surface at the two axial ends thereof respectively and a cylindrical peripheral side surface extending between the first and second end surfaces; forming at least one sensing chamber in the base which has an opening at at least one of the end surfaces; forming a passage in the base which is configured to allow liquid communication between the drill pipe and the drill bit; disposing at least one sensor in the sensing chamber from the opening of the sensing chamber; and sealing the sensing chamber on the at least one of the end surfaces. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention can be understood better in light of the following description of embodiments of the present invention with reference to the accompanying drawings, in which: 
         FIG. 1  is a schematic view of a measurement-while-drilling device in prior art; 
         FIG. 2  is a schematic view of a directional drilling system according to a specific embodiment of the present invention; 
         FIG. 3  is an erection view of a measurement-while-drilling device according to a specific embodiment of the present invention; 
         FIG. 4  is a structural view of a measurement-while-drilling device according to a specific embodiment of the present invention; 
         FIG. 5  is a sectional view of the measurement-while-drilling device in  FIG. 4 ; 
         FIG. 6  is a schematic view of strain gauges of the measurement-while-drilling device in  FIG. 4 ; 
         FIG. 7  is a sectional view of a measurement-while-drilling device according to another specific embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, a detailed description will be given for preferred embodiments of the present utility model. It should be pointed out that in the detailed description of the embodiments, for simplicity and conciseness, it is impossible for the Description to describe all the features of the practical embodiments in details. It should be understood that in the process of a practical implementation of any embodiment, just as in the process of an engineering project or a designing project, in order to achieve a specific goal of the developer and in order to satisfy some system-related or business-related constraints, a variety of decisions will usually be made, which will also be varied from one embodiment to another. In addition, it can also be understood that although the effort made in such developing process may be complex and time-consuming, some variations such as on design, manufacture and production on the basis of the technical contents disclosed in the disclosure are just customary technical means in the art for those of ordinary skilled in the art relating to the contents disclosed in the present utility model, which should not be regarded as insufficient disclosure of the present utility model. 
     Unless defined otherwise, all the technical or scientific terms used in the Claims and the Description should have the same meanings as commonly understood by one of ordinary skilled in the art to which the present invention belongs. The terms “first”, “second” and the like in the Description and the Claims do not mean any sequential order, number or importance, but are only used for distinguishing different components. The terms “a”, “an” and the like do not denote a limitation of quantity, but denote the existence of at least one. The terms “comprises”, “comprising”, “includes”, “including” and the like mean that the element or object in front of the “comprises”, “comprising”, “includes” and “including” cover the elements or objects and their equivalents illustrated following the “comprises”, “comprising”, “includes” and “including”, but do not exclude other elements or objects. The term “coupled” or “connected” or the like is not limited to being connected physically or mechanically, nor limited to being connected directly or indirectly. 
     The terms “may”, “might”, “can” and “could” in the present application indicate the possibility of occurrence in case of some environments, have a certain property, feature or function; and/or by combining with a qualified verb, indicate one or more capacities, functions or likelihood. Correspondingly, the use of “may” indicates that the modified terms are apparently appropriate, matchable or suitable; at the same time, in view of the presence of some situations, the modified term may be not appropriate, matchable or suitable. For example, in some cases, a result or performance may be expected to appear; while in other cases, it may not appear. This difference is embodied in the terms signifying “may”. 
     One aspect of the embodiment of the present invention is adaptable for a measurement-while-drilling device of a directional drilling system.  FIG. 2  is a schematic view of a directional drilling system, which includes a drill rig  33 , a drill pipe  31  and a drill bit  32 . The measurement-while-drilling device  20  is disposed between the drill pipe  31  and the drill bit  32 , in order to detect the information about the drill pipe and the drill bit, and send the information back to a control end, so as to act as the basis of producing a control signal. 
       FIG. 3  is an erection view of a measurement-while-drilling device according to a specific embodiment of the present invention. With reference to  FIG. 3 , the measurement-while-drilling device  20  may be axially connected between the drill pipe  31  and the drill bit  32  of the drill apparatus, and coaxial with both of them. In some embodiment, the measurement-while-drilling device  20  is substantially a cylindrical body. When the drill apparatus is operating, the measurement-while-drilling device  20  rotates with the drill pipe  31  and the drill bit  32 , measures the various parameters for the drill pipe and the drill bit in real time by the sensor(s)  24  therein, forms the drilling data, and transmits the data to a drilling control unit. Then the drilling control unit controls the drilling direction, the drilling speed or the like of the drill apparatus according to the data. 
       FIG. 4  is a structural view of a measurement-while-drilling device according to a specific embodiment of the present invention. As shown in  FIG. 4 , the measurement-while-drilling device  20  includes a base  21  having a rotation axis  211  and having a first and second end surfaces  212 ,  213  at the two ends thereof respectively, a cylindrical side surface  214  extending between the first and second end surfaces  212 ,  213 . In some embodiment, the rotation axis  211  is not a solid shaft, but a straight line in geometry, around which the base  21  rotate. 
     In some embodiment, either of the end surfaces is a plane and is angled with the cylindrical side surface  214 . Further, in some embodiment, the base  21  is substantially a cylindrical body, such that the two end surfaces present circular, and perpendicular to the rotation axis  211 . 
     There are two connecting parts at the two axial ends of the base  21 , such that the base  21  is connected between the drill pipe  31  and the drill bit  32 . Particularly, the base  21  has a first connection part near the first end surface and a second connection part near the second end surface, which are used for coupling with the drill pipe  31  and the drill bit  32  respectively. 
     With reference to  FIG. 3 , in some embodiment, the first connection part is a protrusion part  215  protruding form the first end surface  212 . There are male threads  2151  on the curved surface of the protrusion part  215 , and female threads  311  on the drill pipe  31  for matching with the male threads  2151 , such that the base  21  and the drill pipe  31  are connected by the threads  2151  and  311 . The second connecting part is a recessed part  216  recessing inwards from the second end surface  213 . There are female threads  2161  on the inner wall of the recessed part  216  and male threads  321  on the drill bit  32  for matching with the female threads  2161 , such that the base  21  and the drill bit  32  are connected by the threads  2161  and  321 . 
     In some embodiment, the protrusion portion  215  may be a cylindrical body, or a truncated cone as shown in  FIGS. 3 and 4 , but not limited to this. The protrusion portion may be a cylindrical cavity with a half enclosed, or a truncated-cone cavity as shown in  FIGS. 3 and 4 , but not limited to this. 
     In this embodiment, the base  21  is connected with the drill pipe  31  and the drill bit  32  in a threading way, but not limited to this. The base  21  may also be connected with the drill pipe  31  and the drill bit  32  in other ways such as by snaps, bolts or the like. 
     The base  21  defines a passage  23  therein for the liquid communication between the drill pipe  31  and the drill bit  32 . In some embodiment, as shown in  FIGS. 4 and 5 , the passage  23  goes through the base  21  along the rotation axis  211  and presents a cylindrical cavity coaxial with the base  21 . 
     With reference to  FIG. 3 , the base  21  further defines at least one sensing chamber  22  therein for accommodating the sensor(s)  24  of the measurement-while-drilling device. The sensing chamber  22  has at least one opening  221  on the first end surface  212 . The opening of the sensing chamber in prior art as shown in  FIG. 1  is located on the cylindrical peripheral side surface. In such a way, the installation and maintenance of the sensor  12  is convenient, but because of the assemblies such as the cover  13  near the sensor  12 , there may be unpredictable and very unstable inner force among the assemblies or between the assemblies and the base, which may reduce sharply the measurement accuracy of the sensor  12 . In addition, there is a complex connection between the cover  13  and the opening of the groove  11 , hence the sealing performance of the equipment cannot be ensured. In contrast, in the present invention, there is no opening on the cylindrical peripheral side surface  214 , and the sensor  24  is disposed near the axially middle portion of the base  21 . In this way, when the sensor  24  is placed into the sensing chamber  22  from the opening  221 , the structure near the cross section of the sensor  24  perpendicular to the rotation axis  211  is simple and stable, and there is no other assemblies than the base  21  to interact with the sensor, such that there is no undefined or unstable inner force to affect the measurement accuracy of the sensor  24 , thereby improving the measurement accuracy of the sensor  24  greatly. 
     Continuing to see  FIG. 3 , at least one sensor  24  is disposed within the sensing chamber  22 . In some embodiment, the sensor may be a strain component, a 3D (three-dimension) accelerometer, or the combination thereof, and dependent on the requirements, it may be other type of sensor or the combination thereof, but not limited to it. 
     With reference to  FIG. 4 , the measurement-while-drilling device further includes a sealing member  26  disposed on the end surface for sealing the sensing chambers  22 . In some embodiment, the seal  26  includes a cover  261  and a sealing pad  262  on the at least one end surface. The sealing pad  262  is disposed between the cover  261  and the at least one end surface for improving the sealing effect of the cover  261 . 
     With reference to  FIGS. 4 and 5 , furthermore, in some embodiment, the four cylindrical sensing chambers  22  pass through the cylindrical base  21  along the direction of the rotation axis  211 . Each of the sensing chambers  22  has two openings  221 ,  222 , disposed on the first and second end surfaces  212 ,  213  respectively. Each of the end surfaces  212 ,  213  is disposed with a cover  261  and a sealing pad  262 , both of which are annular, in order to cover the four openings on each end surface, and free the impact on the operations of the connection parts  215 ,  216  and the passage  23 . 
     In some embodiment, each of the sensing chambers  22  has a shape in conformity with the cylindrical peripheral side surface, such that the interior space of the base  21  can be made full use of, and the inner volume of the sensing chamber  22  can be increased. With reference to  FIGS. 4 and 5 , the base defines four cylindrical sensing chambers  22  between the outside of the passage  23  and the cylindrical periphery side surface  214  of the base  21 , which are disposed evenly around the passage  23  and each of which has a cross section of long curved ellipse. 
     In some embodiment, the sensor  24  includes at least two strain components  25 . As shown in  FIGS. 4-6 , each of the strain components  25  includes a first, second and third strain gauges  251 ,  252 ,  253  disposed on the inner wall of the sensing chamber  22  along three different directions, for measuring the pressure, moment, side force or the like, of the drill bit. By such a combination of the strain components, various forces and moments on the drill bit may be separated, which further improves the measurement accuracy. 
     In some embodiment, the first, second and third strain gauges  251 ,  252 ,  253  are mounted on the side of the inner wall of the sensing chamber  22  near the cylindrical periphery side surface  214 . As shown in  FIG. 5 , each of the strain gauges has a larger deformation amount on the side near the cylindrical periphery side surface  214  than on the other side, such that the signal to noise ratio of the strain component  25  can be increased, and the measurement accuracy can be improved. 
       FIG. 6  is a schematic view of strain gauges  25  of the measurement-while-drilling device. As shown in  FIG. 6 , the first and second strain gauges  251 ,  252  are symmetric to the third strain gauge  253 . In some embodiment, the angle between the first strain gauge  251  and the third strain gauge  253  is about 45 degree, such that the angle between the first strain gauge  251  and the second strain gauge  252  is about 90 degree, which makes the calculation simple, and improves the precision of the measured results. 
     In some embodiment, the sensor  24  further includes one or more pairs of 3D accelerometers, wherein each pair of 3D accelerometers are disposed symmetrically to the rotation axis  211  of the base, and by the combination of two 3D accelerometers, the motion parameter and the vibration parameter of the rotation of the drill bit is separated. In particular, by adding the signals of each pair of 3D accelerometers, the centrifugal acceleration of the two 3D accelerometers is counteracted, so as to eliminate the negative impact produced by the centrifugal acceleration of a single 3D accelerometer, such that the measurement accuracy of the measurement-while-drilling device  20  for the vibration is improved. In addition, the rotation speed of the drill bit may be measured more accurately through the subtract of the signals of each pair of 3D accelerometers. 
     In some embodiment, the 3D accelerometers may be integral, or replaced with three one-dimension accelerometers, or with one two-dimension accelerometer and one one-dimension accelerometer. 
     With reference to  FIG. 7 , in some embodiment, the measurement-while-drilling device  20  includes two 3D accelerometers  271 ,  272  disposed along the same line through the rotation axis  211 , and distant equally from the rotation axis  211 . 
     The sensor  24  and the sensing chamber  22  are employed for obtaining the drilling data and transmitting the data to a drilling control unit, wherein the drilling data is transmitted via cables, ultrasonic wave, acoustic signals, or radio-frequency signals. In some embodiment, the sensor  24  may be supplied with power via cables or batteries in the sensing chamber  22 . 
     Another aspect of the present invention relates to a method of obtaining hydrocarbon by a drill apparatus including the measurement-while-drilling device, comprising: designing a predetermined drilling trajectory which leads to hydrocarbon to be produced; drilling a well bore with the drill apparatus comprising a measurement-while-drilling device based on the predetermined drilling trajectory; removing the drill apparatus from the well bore; and obtaining the hydrocarbon from the well bore. 
     The step of drilling a well bore with a drill apparatus comprising a measurement-while-drilling device comprises: obtaining drilling data with the measurement-while-drilling device; transmitting the drilling data to a drilling control unit; and calibrating a drilling direction of the drill apparatus based on the drilling data and the predetermined drilling trajectory. 
     In some embodiment, the step of transmitting the drilling data comprises transmitting via cables, ultrasonic wave, acoustic signals, or radio-frequency signals. 
     In some embodiment, the method further comprises encoding the drilling data before transmitting them. 
     Another aspect of the present invention further relates to a method for producing a measurement-while-drilling device, comprising: providing a base having a rotation axis, configured to be axially connected between a drill pipe and a drill bit of a drill apparatus and having a first and second end surfaces at the two axial ends thereof and a cylindrical peripheral side surface extending between the first and second end surfaces; forming at least one sensing chamber in the base which has an opening at at least one of the end surfaces; forming a passage in the base which is configured to allow liquid communication between the drill pipe and the drill bit; disposing at least one sensor in the sensing chamber from the opening of the sensing chamber; and sealing the sensing chamber on the at least one of the end surfaces. 
     In some embodiment, the method further comprises forming a first connecting part near the first end surface and forming a second connecting part near the second end surface, for connecting the base with the drill pipe and the drill bit of the drill apparatus. 
     Although some specific embodiments have been described as mentioned above, the skilled in the art understand that various modifications and variations may be made. Accordingly, it should be noted that the claims are intended to cover all the modifications and variations within the actual concepts and scopes of the present invention.