FR2465065A1 - Drilling tool angle inclination indicator - has drill collar device which is hollow for mud flow path which creates sensed output - Google Patents

Abstract

The tool incorporates an outer shell which is connected in a drill string above the drill bit and among the drill collars. The device utilises mud pressure variations to pump oil with a piston to energise a closed hydraulic circuit. The oil is delivered via a distribution and manifold system to first fill and scan five hydraulic signals sequentially. The sequential scan of the five hydraulic signals is conveyed to an output mechanism comprising a choke which is placed in the lower end of the tool. The choke varies the mud throughout and thus upstream pressure in the mud circuit, forming an output which can be detected at the surface.

Description

 The present invention relates to a simultaneous measurement drilling tool. Various simultaneous measurement drilling tools have been produced in the past. The present invention provides improved performance over these. First of all, this tool does not require internal electrical mounting, batteries and the like. In some wells, the temperature at the bottom of the hole is so high that electrical components are severely disturbed and do not function satisfactorily. The present invention is able to operate quite satisfactorily at high temperatures because it does not include batteries or electronic components.

The present invention is in particular able to provide an indication of the angle of inclination of the tool. In addition to this, it produces an output signal representative of the progress relative to magnetic north. Other output devices are incorporated. One of the best and most desirable sensors is a mechanism to indicate the tilt of the tool. This is particularly useful for determining whether or not the tool is oriented vertically or at another angle deviating from the vertical. When drilling for oil wells, it is often necessary to control their drive or direction. Sometimes they are intentionally moved away from the vertical0 In any case, this must be indicated on the surface to control the deviation. Techniques exist allowing to measure a drift or an angular deviation from the vertical.

Other sensors can be used. In each case, regardless of the particular nature of the sensors, it is very useful to incorporate in addition devices which generate two calibration pulses. The calibration pulses serve as a reference or standard against which the variables can be calibrated. Two are particularly useful.

This is useful for calibrating the output signal that is read from the mud pressure line connected to the drill string. The attenuation varies as the well is drilled deeper and deeper. As drilling progresses, it is necessary to compare the available calibration signals. The viscosity of the slurry column encountered when the well becomes deeper can vary and thus modify the signals detected on the surface, but as long as the calibration output signals are available, they serve as a comparative standard, and data can be read from the surface.

The present invention is a sleeve type drilling device in its external appearance. I1 is connected to a drill string, having standardized API plugs or sleeves. I1 is hollow over its entire length to constitute a circulation path for the drilling mud. I1 draws its power from the drilling mud by presenting a piston sensitive to the mud pressure so that each drop in mud pressure when stopping and restarting the pump pressurizes the movable piston and the system hydraulic oil. Hydraulic oil powers the equipment. The output signal is created by modulating a plug in the mud flow path through the tool. It opens and closes to narrow the mud flow path, creating an upstream pressure variation which is detected at the surface.

 Figure 1 is a side view, partly in section, of the tool of the present invention which resembles a drill sleeve.

 Figure 2 is a hydraulic diagram of the device, showing in particular how the variables are converted into hydraulic signals.

 Figure 3, which consists of segments 3A to 3H, inclusive, is a detailed longitudinal sectional view showing the components of the present invention.

Figure 4 is an enlarged sectional view showing a member for determining the azimuth of the tool.

Figure 5 is a sectional view, in addition to the
Figure 4, which shows a tubing system.

Figure 6 is a sectional view of hydraulic lines and valves.

Figure 7 is an alternative embodiment to that of Figure 2.

 The embodiment shown in the drawings serves as a device for capturing dynamic data and transmitting signals from a borehole, which operates without batteries, electronic components and the like. At rest, it is passive in the sense that it does not require an effective source of power. Each time the surface mud pumps are turned off and the mud pressure drops, this device samples all the data. When the pumps are restarted and a sludge circulation is restored, data is transmitted to the surface together with two calibration signals. The calibration signals represent the minimum and maximum values of each of the transmitted data. After transmission of all the data and the two calibration signals; the device stops and remains inert until the sludge flow is stopped again, the process then being repeated.

In FIG. 1, the apparatus is designated by the reference number 10. I1 is open at the upper end 11 to delimit an axial passage through which the drilling mud flows. The drilling mud flows through the tool and escapes at the base0 The entire tool has a diameter which adapts to the drill sleeve of the drill string. It has sufficient cross-sectional area to allow the mud to flow through without creating excessive back pressure.

It includes, however, a plug which selectively throttles the outlet passage so that the mud flow is pulsed and thereby forms an output signal. The mud, of course, flows through the tool shown in Figure 1 from top to bottom, and when it escapes through the base1 it flows into the next element of the chain of rods of drilling.

The tool 10 is typically installed among several drill sleeves just above a drill bit. The number, size and weight of the drill sleeves can be changed according to the specifics of the drilling program. In each case, the present invention has the external appearance of a drill sleeve and operates somewhat in the manner of such a sleeve. I1 may not have the same weight1 but it includes the apparatus which will be described below for measuring certain variables during drilling1 and, for this purpose, it is preferably placed relatively close to the drill bit,
The equipment of the present invention operates under difficult conditions, and therefore is made very robust. Its robustness is increased by using a device that operates without electronic components, batteries or similar devices.

 For a better understanding of the structure, attention is now drawn to the detailed representation of the top of the tool 10. This representation is in several parts and begins with Figure 3A.

In FIG. 3A, the measurement tool 10 incorporates the axial passage 11 which opens below the standard threaded connection. The opening 11 communicates with a concentric passage 12 extending along the tool for delivering the mud. The total cross-sectional area of passage 12 is sufficient to prevent blockage of the flow of drilling mud. A tubular body 13 is closed by a plug 14 at the upper end. The body 13 is hollow, cylindrical and placed concentrically in the annular passage 12. The plug 14 closes it completely. A lifting eye is shown on the upper end. The plug 14 closes an internal cavity or chamber 15. The chamber 1S is intended to receive and store oil.

Oil fills chamber 15.

A constriction controls the passage of the mud.

 I1 is constituted by the shoulder 16. The shoulder 16 is fixed to the external body 17. The body 17 is a tubular, elongated body which surrounds or receives the measuring tool 10. In addition, it is the outside which undergoes all the wear and tear encountered by the device of the present invention.

 The throttle 16 is used to create a certain back pressure so that the pressure is undergone by the plug 14. The plug is pushed down to the limit of displacement to thereby regulate the hydraulic system.

 The tubular body 13 is free to move.

Its movement is forced. I1 fits over a slightly smaller tubular element 19. The tubular element 19 is shown in the lower part of Figure 3A. It will be noted that the tubular elements 13 and 19 have overlapping or locked shoulders. The shoulders abut each other to limit an upward movement. Thus, the plug 14 can be pushed down by the pressure of the mud. I1 rises by the action of a spring 20. The spring 20 is a return spring which brings the shoulders into contact with one another at 21. The shoulders 21 thus limit an upward movement, and this is shown on Figure 3A. A downward movement is obtained against the spring 20 which is compressed. The spring 20 is thus a helical spring serving as a return mechanism.

 The spring 20 is enclosed in a guide tube 23. The tube 23 has a length sufficient to contain the spring. The spring fits around a reinforcing rod 24. The rod 24 is positioned in the spring so that the latter is held concentrically with the tubular casing 23. The tubular casing 23 descends before the external tubular casing 13 does so . During the ascending race, they move together. The tubular boot 23 is chamfered at 25 to allow it to surround the helical spring 20, functioning somewhat like a funnel. Thus, the tubular housing 23 which moves up and down must pass over the different turns of the spring.

The tubular element is concentric inside a larger tubular element 26. The tubular element 26 is equipped with an upper shoulder 27 which is directed inwards, while the tubular element 23 has a shoulder lower 28 which extends radially outward around it0
The shoulders 27 and 28 are fitted. That is, the tubular element 23 cannot rise too high or escape. Its exhaust is limited, and, consequently, an axial deployment is limited by embedding the shoulders 27 and 28. This traps the spring 20 to prevent it from escaping.

 Ports 30 allow the oil to fill the concentric annular cavity between the shoulders 27 and 28.

The measuring tool 10 further comprises an annular passage 31 which carries the drilling mud on the outside of the moving parts. Suitable annular seals at 32 prevent leakage.

Chamber 15 is an oil tank. Its volume is reduced when the plug 14 descends. The chamber 15 opens into a small passage 33 shown in the
Figure 3B. The passage 33 is a relatively narrow, concentric annular flow space. The flow space is on the outside of a solid cylindrical element 35. The element 35 is joined to the rod 24. In addition, it is externally threaded so as to produce a threaded connection at 36 to fix the fixed tubular element 26. The element 35 is hollow with an axial passage 37 which opens into two or three lateral orifices ending around the base of the rod 24.

The orifices 38 are connected to the axial passage 37 which opens into the central tubular element 23.

 The element 35 is moreover joined to an external tubular sleeve 40. The sleeve 40 is centered by lugs 41 arranged spaced at its periphery It is centered inside the external body 17. The lugs 41 interrupt the external path of flow of mud. Three or four relatively thin legs are sufficient. They maintain and center the tubular element 40. The tubular element 40 constitutes a type of assembly for the various concentric elements described above. It is screwed onto the internal element 35 by a threaded connection 42. The tubular element 40 also fixes the external fixed tubular element 19 by means of a threaded connection at 43. It will be noted that the connection 43 is protected by Ring seals at both ends. The same is also true for threaded fittings at 42 and 36.

The passage 33 is thus made between the internal element 35 and the tubular element 40 around it.

The passage communicates with an internal passage 46 which extends inside the element 35 and is connected to a longitudinal passage 47. The passage 47 is parallel to the aforementioned passage 37. Although they are parallel, they do not intersect.

The passage 47 opens into a cavity or chamber 48. This is a high pressure hydraulic oil system, and includes a reservoir at 48. An accessory 49 is suspended from the lower end of the central element 35, and is connected to a tube 50.

The oil flowing through the passage 37 and the tube 50 will be called low pressure oil. It is at low pressure compared to the pressure prevailing in the tank 48.

In this case, the device will be described according to the physical positioning of the constituents. It will not however be described as a hydraulic system which is better and more easily described with reference to the hydraulic diagram incorporated in the drawings.

However, with regard to the positioning of the constituents, this can be explained satisfactorily. The components located on the lower part of Figure 3B, the whole of Figure 3C, and the upper part of Figure 3D are mounted in a hydraulic circuit where several pipes are located near the internal wall of the cavity or chamber 48 They are all supplied with pressurized oil as will be described.

 The upper measuring device is shown in Figure 3B, and it is a column-shaped device referenced 52. It is a closed cylindrical container in Figure 3B. The container encloses and surrounds the transducer located in the case 54 which is fixed by a flange 55 to a mounting rib 56 extending transversely. The rib 56 is perforated to allow the oil to flow through. The rib 56 further carries a support 57 on its lower side which is joined to the rib 56 by suitable bolts 58. The bolts 58 pass through the rib and also fix the flange 55. The rib 56 is not solid but has openings as will be described in connection with Figure 4.

 Figure 4 is an enlarged sectional view through the member 52. The member 52 serves as a progress indicator. The apparatus shown in Figure 4 thus begins with an intake pipe 60 where oil is supplied under pressure from a source to be described. They are delivered to a sleeve 61 which surrounds the end of a hollow tubular accessory 62. The accessory 62 has an axial passage for receiving a tube 63. The tube 63 extends in a transverse end closure plate 64. The plate 64 constitutes the upper end of the box or case and further supports a wall 65. The wall 65 constitutes the outer envelope of the container. It serves as a cylinder. An internal cavity is defined at 66. The cavity 66 is adjacent to a movable piston 67. The piston 67 moves and thus varies the volumetric capacity of the cavity or chamber 66.

 Oil is introduced under pressure through line 60 and flows into line 63.

It is delivered externally via a side passage 68. The passage 68 is selectively connected to an annular passage 69 and to a rare passage 70. The radial passage 70 evacuates the hydraulic oil under pressure flowing through a check valve 71 which, in turn, conveys the oil coming from the chamber 66. The cylindrical space 66 is dimensionally modified by displacement of the piston 67.

The passage 68 is made in a small piston 72. The piston 72 is trapped in the piston 67 of larger dimensions. It is shown at the upper end of its travel and is made airtight by the operation of a seal on the upper face.

The piston 72 is free to move down against an elastic ring 73. The latter limits its movement down. Its upward movement is limited by the concentric shoulder cut in the piston 67. The piston 72 carries a projecting rod 74 which is concentric at its center and which extends downwards to one end. It passes through an opening in the transverse rib 56. The rib 56 is perforated centrally to create an internal gap suitable for the rod or probe 74 extending through it, and the lower case 57 is, of course, fixed to the lower side.

 The mounting rib 56 holds a transverse plate 75. The plate 75 is perforated axially centrally to allow the passage of the probe 74. In addition, a bearing 76 supports an axis 77 on a drum 78. The drum 78 supports a helical cam 79. The cam extends over the entire periphery of the drum and thus embraces 360-. The cam is an areshing lip of a sufficient distance from the surface of the drum 78 to receive or block the probe 74. As will be described later, the probe 74 moves downward. Its downward stroke is limited by the cam 79. Depending on the location of the cam as a result of a rotation, the probe can move a short distance, or, as a variant, it can extend over a large distance. In each case, the cam 79 embraces 3600 around the drum 78. The minimum movement is equal to zero, the longest stroke is equal to 3600.

The reference number 57 designates a fixed support. This support carries a bearing 80 which, in turn, receives an axis 81 passing through it. The axis 81 is aligned with the axis 77 to support the drum 78. The bearing 80 is thus in a milled opening and held in position by the parallel branch 82 of the support 57
The axis rotates a spur gear 83 which meshes with a second spur gear 84. The spur gears 83 and 84 have a 1: 1 ratio. The right pinion 84 is mounted on an axis 85. The axis 85 is kept in alignment by a bearing 86 which is located in the parallel branch 82. A second bearing 87 surrounds the axis 85.

The bearings 86 and 87 align the axis 85. In addition, it is kept in axial alignment with the probe 74.

Thanks to the use of straight pinions, the rotation of the axis 85 is transmitted to the drum 78. They rotate at the same angular speed, this being the result of the 1: 1 ratio between the two pinions. Consequently, one complete revolution of the axis 85 rotates the drum 78 by one full revolution.

The axis 85 is connected by means of a yoke 88 to a universal joint. The universal joint is located in the center of a two-dimensional gimbal system. The gimbal system comprises a fixed bearing at 90 supporting a pin 91, and a similar device is provided at the opposite end. The axis 91 supports an internal cardan ring 92. The cardan ring 92 extends over a complete circle and thus supports a perpendicular mounting axis 93. The axis 93 is opposite a similar axis on the other c8té. The two axes 91 are perpendicular to the axes 93. Thus, there are two external axes projecting outwards from the cardan ring 92
They define a first axis of rotation. The axis 93, supported by a suitable bearing on the inside of the ring 92, constitutes a second axis of rotation perpendicular to the first. The universal joint assembly thus comprises two perpendicular axes of rotation which are separated by cardan rings. In addition, the axis 85 is attached, by means of a yoke 88 forming part of a universal joint thus supporting an axis 95 extending downward which hangs freely vertically and however transmits a rotation to the axis 85. More particularly, the vertical axis 95 will rotate and transmit its rotation to the axis 95, even if the axes 85 and 95 are not parallel. The axis 95 is used as a mounting axis for a heavy pendulum, of large dimensions 96. The pendulum 96 adds weight to ensure that the axis 95 is suspended in a direction determined by the vertical component of the vitreous gra. The weight 96 is heavy enough to keep the axis 95 vertical. The pendulum 96 is equipped with a transverse magnet comprising a north pole in 97 and a south pole in 98. The magnet is strong enough to be attracted by the magnetic field terrestrial and thus rotate the pendulum 96. When it turns, it rotates the axis 95. This rotation is transmitted, via the universal joint 88, to the axis 85.

Its rotation, in turn, is transmitted, via the right pinions 83 and 84, to the drum 78.

It rotates the drum to position the cam 79 for contact by the probe 74.

 If the measuring tool 10 is normally used vertically, no problem arises for the transmission of the pendulum rotation and for its alignment with the magnetic field. However, it may be in an oblique hole. If this is the case, the pendulum will deviate laterally or deviate from the axis of the tool. This is not a problem since it can be suspended vertically by the operation of the two-dimensional gimbal system. However, the rotation is transmitted via the universal joint.

 The pendulum is heavy enough to hang vertically, and the magnet provided therein is powerful enough to seek alignment with magnetic north. To this end, the external parts of the tool should be made near the magnets 97 and 98 in monel or other metal which does not mask the magnet vis-à-vis the earth's magnetic field.

 The outer surface of the pendulum is made in steps. It is cut according to a particular profile. Reference number 99 designates a center probe extending upward for the purpose of determining the angle of inclination. The probe 99 is connected to the equipment indicating the inclination. This equipment is quite similar to that shown in 52, except that it is reversed. In other words, probe 99 corresponds to probe 74 at the top of Figure 4.

The probe 74 is pushed down under the action of hydraulic pressure until it comes into contact with the cam 79. On the contrary, the probe 99 moves up until it comes in contact with the pendulum 96. If the tool is perfectly vertical, as determined by the gravity positioning of the pendulum 96, then the probe 99 is deployed to the minimum. The probe 99 is limited by the profile of the external surface of the pendulum. The pendulum has a number of steps in 100. The first step can correspond to an angle of inclination of one degree. This rung is located at a particular distance from the probe 99. In other words, the probe 99 is represented according to its minimum displacement corresponding to an inclination of oe. When the probe deploys to come into contact with the next rung, it deploys to a specified length; for example 5.08 mm.

The inclination is incrementally identified by increasing steps. When the angle of inclination with respect to the vertical increases, the probe 99 collides with a more distant step and thus converts the angle of inclination into linear movement of the probe 99.

 The steps 100 extend all around the pendulum 96. Thus, each constitutes a plate cut in the outer surface having a height difference equal to the calibrated standard. A deviation of the pendulum from the axial position shown in Figure 4 thus constitutes a surface for the probe 99. Each rung is cut normally to a radial straight line starting from the pivot of the gimbal system and perpendicular to the end of the probe.

The probe 99 is shown in the lower part of Figure 3B. A mounting rib 101 extends over the interior of the chamber. The rib 101 is parallel to the aforementioned rib 56. The two ribs are placed on the inside of a long thin-walled tube inside a hollow tubular element 102 which is screwed at 103 onto the above-mentioned tubular sleeve 140. The threaded connection is protected by suitable annular seals to prevent leakage. The tubular sleeve 102 is located on the inside of the external body 17 to delimit an annular chamber 105. The annular chamber 105 is the space in which the mud circulates through the tool.

 Attention is now drawn to Figure 3C where the reference numeral 100 denotes the housing of the tilt coding device which is attached to the transverse mounting rib 101. The device is identical to the device for indicating d advancement 52 previously explained. I1 is also equipped with a suitable hydraulic supply pipe 107.

The connection of this pipe will be described in detail later.

 The reference number 108 designates another hydraulic pipe similar to the pipe 107.

It is connected, via the sleeve similar to the one at the top of Figure 4.

It delivers hydraulic oil for the operation of an orientation device 111. The orientation device 111 is mounted on a transverse mounting rib 112. It has a closed housing which is similar in construction and to operation. device better represented in Figure 4. That is to say, it implements a piston inside a piston device having a protruding probe. The probe extends as close as possible to a drum 113 carrying a helical cam 114. The helicoRdale cam is rotated in a particular position determined by a pendulum arm 115. The arm 115 is supported on an axis, appropriate bearings aligning the axis and the drum 113 for rotation. Here again, the same embodiment as that shown in FIG. 4 is used to support the drum 113. To this end, a mounting support 116 extends from the side lower of the mounting rib 112. It includes bearings suitable for reducing friction.

 The arm 115 has a sufficient weight causing it to hang down. It will hang down continuously without interruption at any time when the tool is not vertical. If the tool is perfectly vertical, it will take any position it had before. Such a reading is meaningless. It is meaningless because it appears at a time when the pendulum 96 hangs vertically, and the tilt signal is representative of the vertical position of the tool. The orientation angle is referenced relative to a fixed key in the tool to be compatible with respect to tool 10.

Figure 3C further includes an additional signal generating apparatus which is supplied by a hydraulic line 117. It is the apparatus indicated at 118 which generates a short calibration output pulse. It is mounted on a suitable mounting rib 219 which extends transversely from one edge to the other of the tool, continuing with the
Figure 3D, an additional hydraulic line 120 delivers hydraulic oil under pressure for a long calibration device 121. The devices 52, 106, 111, 118 and 121 all operate in the same way, that is to say that they use the piston inside a previously described piston device. They code different measures. The members producing the signals 118 and 121 form calibration pulses. One is short, and the other is relatively long.

 The reference number 122 designates a chamber which communicates with the interior of the tool comprising the chamber 48 above. It is spanned, but not closed at the upper end, by the mounting rib 123. The signal generator 121 is mounted above it. In the chamber, a cylinder 124 surrounds a movable piston 125. The piston is exposed to the oil in the chamber. The piston 125 is mounted on a rod 126. The rod 126 transmits the movement of the piston 125 to an enlargement 127 shown in Figure 3E. The widening 127 is supported on the lower end of the piston rod 126.

 The piston rod 126 is guided by an element 130 which is fixed to the lower end of the sleeve 124 by a threaded connection 131. This closes the lower end of the cylindrical element 124. The threaded connection 131 is protected by suitable ring seals at both ends of the thread. The annular seals are seals and also serve as hydraulic locks. The hollow element 130 is perforated axially by a passage allowing the piston rod 126 to pass through it. The piston rod supports the widening 127 below the hollow element 130. The widening 127 is made in a hollow tubular element 132. The hollow tubular element 132 is a central appendage below the hollow element 130, and it has a sufficient length to take account of the stroke of the enlargement 127.

 The enlargement 127 serves as an operating member.

 I1 moves in front of a lug 133 which projects in its path. The apparatus comprises seven valves, one being represented by way of example in FIG. 6 valves which are better represented on the hydraulic diagram of FIG. 2. Each valve is in two positions, actuated by lug, biased by spring.

They are mounted on the outside of the tubular element 132 and comprise the protruding lug which actuated by the widening. The enlargement 127 has a dimension and a shape which pushes the lug aside, overcoming the stress of the spring and opening the valve. There are seven of them and they are all identical, except that their position varies along the tubular element 132.

 Five of the seven valves are associated with the five signal generators. A sixth valve serves as a fill valve, and the seventh valve is a discharge valve. The tubular element 132 is open at the lower end, The widening 127 moves over the entire length of the tubular element 132. I1 is recalled by bringing the piston 125 towards the upper end of its stroke as shown in the Figure 3D. I1 is pushed upwards by introducing pressurized oil into a line 136. The line 136 is applied to a throttle 137. In addition to the throttle 137, the line 136 branches off to another inlet throttle 139 and a check valve 140 in series is in communication with the chamber below the piston 125. This arrangement of the check valve 140 and the two inlet throttles allows a faster upward stroke and a controlled downward stroke.

 Each valve is thus shown mounted on the side of the tubular member 136. Six are located on the left side of Figure 3E, and the last, which is an unloading valve, is located on the lower right end. It is the last element to be contacted by enlargement. When in operation, the pressure is discharged from chamber 15 to an accumulator.

Attention is momentarily drawn to the
Figure 2. The piston 125 and the enlargement 127 moved by it are referenced. The line 136 ends at a cylindrical element 124 for pushing the piston 125 towards the upper end of its stroke. The widening 127 is appropriately positioned with respect to the seven valves and the most distant of the seven from the latter in the diagram is the relief valve 145.

The discharge valve is normally closed when the expansion 127 meets it, at which time it opens. When opened, hydraulic oil from the check valve 146 flows to the line 136 and to the reservoir. The line 136 delivers hydraulic oil below the piston 125 (see Figure 3E) to bring it back towards the upper end of its stroke. 0 When it moves, it strikes all the pins and triggers each valve. It moves until it reaches the end of its stroke. At the end of its stroke, it triggers the filling valve. This valve is referenced 147. It is connected by a short pipe 148 to pipe 136. The valve is connected by pipe 149 by means of a check valve suitable for the high pressure source. equipment will be described later.

 Referring now to Figure 3E, all of the lug actuated valves, except those associated with filling and discharging, connect to a common line 150. The line 150 passes close to the lug operated valves on the side left of the figure. The pipe 150 ends at a control orifice 151. The control member 151 is enclosed in a hermetic case which is supported by the transverse mounting rib 152 shown at the top of FIG. 3F. For an understanding of this equipment, attention is drawn to Figure 5.

 The control member 151 comprises a closure cap 154 at the upper end. The plug 154 is held in position by an elastic ring. A suitable annular seal around its outer periphery prevents a leak between it and the cylindrical body surrounding it 155. The pipe 150 opens, via an orifice, into a chamber. The line 150, constituting a collective tubing, delivers oil near a piston 157. The piston 157 is received in the tubular container or external casing 155. I1 is pushed upwards by a helical spring 159. The spring leans against a peripheral lip of the piston.

The spring is supported by a shoulder 160. The shoulder 160 is located at the base of an enlarged chamber inside the hollow cylindrical element 155.

 The piston 157 has a large skirt at the upper end and is reduced to a smaller diameter. It has several steps so that the skirt at the upper end is the widest, the part 161 is smaller, - the part 162 is even smaller, and the part 163 is even smaller. Part 163 is a relatively long hollow pipe attached to the lower end of the piston.

The enlargement 162 defines a shoulder on a helical stop spring 165. The helical spring 165 rests against a sliding ring 116. The ring 166 is carried by the probe 163. Because it moves with the enlargement 162 which carries the other shoulder confining the helical spring 165, the spring usually has a fixed extension. It does not flex or lengthen. This is true under ordinary conditions. However, when the piston 157 travels an adequate stroke, the ring 166 touches the bottom. The ring usually rests on an elastic ring in the tubular element 163. It touches the bottom against the shoulder 167. The shoulder 167 is hermetic with respect to the ring 166 which comprises a seal.

The gasket is incorporated to prevent flow along the probe 163.

In operation, a variable quantity of oil is discharged from a transducer when it is interrogated and is supplied through the valves actuated by lugs in Figure 2, supplied via the tubing 150 is applied above of piston 157. Piston 157 is moved when oil is introduced. The oil flows beyond the piston through a constriction 169. The constriction 169 is connected to and in parallel with a check valve 170. The valve 170 opens into an axial passage 172 which is also connected to the constriction 169 The passage 172 extends over the entire length of the tubular extension 163. A more detailed explanation of this will be given later.

 Reference numeral 175 designates a transverse mounting rib. It supports the housing 155.

The housing 155 is connected to it by suitable mounting lugs and bolts at 176. The tubular housing 155 is tapped at 177 and supports a lower tubular case 178 below. The tubular housing 178 extends upwards to the shoulder 167. Thus, the seal 166 is carried against the shoulder 167 to selectively close the external passage around the tubular extension 163.

 The conduit 136 opens into the tubular case 155 at a 1SO connection. The fitting introduces oil on the outside of the piston 157. The oil flows from the conduit 136 and into the passage 172. If the piston is high, the sealing ring 166 is raised, and oil can flow through passage 182, which is the annular passage surrounding the tubular extension 163 at the base of the piston. Thus, there are two passages in the assembly shown in Figure 5. One is on the inside at 172 and the other on the outside in 182. The outside passage is made active by upward movement of the ring The oil flows through the annular passage 182 from the enlargement 183. The enlargement 183 is made in the lower tubular element 178 which has the same outside diameter as the cylindrical case 155. enlarged receptacle 183 in the form of a ring is connected by a lateral orifice 184 to a tube 185. The tube 15 delivers oil from below as will be described. The tube 185 is connected, by means of a suitable fitting which is fixed by an elastic ring in a countersunk opening of the body 178.

 From the above, we understand how the canali station 136 always conveys oil to the tank. The pipe 185 is controlled by a valve, which occurs when the sealing ring 166 is in the high position shown, and such communication is cut off when it is in the low position.

 The apparatus of Figure 5 is surrounded by pressurized oil. The reference number 186 designates an orifice from the outside to the inside for introducing oil. This hydraulic fluid is under pressure, and the source serves as a reservoir. The roll is introduced under pressure into an enlarged milled passage 187. The passage 187 has an upper shoulder 188 and a lower shoulder 189. These shoulders enclose the sealing seals 190 and 191 between them. The seals 190 and 191 are sealing rings around the tubular element 163 which are free to coalesce. They are spaced from each other by a spring 192. Each is limited in position by an elastic ring placed in a groove around the hollow tubular extension 163. It will be noted that the seals are active when they are around the shoulders 188 and 189. No hermetic seal is made until they are in contact with the facing shoulder.

The shoulder 189 is the upper end of a threaded lower housing 194 which is the last constituent of the assembly shown in FIG. 5. It is joined by threads in 195 to the intermediate tubular element 178. Here again, it will be noted that the elements 155, 178 and 194 have a common outside diameter to delimit the hermetic assembly shown in Figure 5. Seals are incorporated on the threaded connections 177 and 195 to prevent leakage.

The passage 186 is selectively placed in communication with the outlet passage 185 when the seal 190 is low. Alternatively, oil introduced through passage 186 will flow down into the internal annular space 196 which is an extension of the annular space 182 located above. Access thereto is selectively controlled by the sealing ring 191. When the movable tubular element 163 is in the low position, the sealing ring 191 is closed. The passage 196 extends downward to an enlarged internal cavity, similar to a ring, 197.

An orifice 198 is made in the body 194, and it communicates with a countersunk opening where a fitting 199 is placed receiving a conduit 200. The conduit 200 extends below for a purpose which will be explained.

 The tubular body 194 has an internal shoulder 201 which is turned downwards, and a threaded end plug 202 is placed against it. The plug 202 closes the lower end of the interior of the tool. The plug 202 is hollow so that a conduit 203 can be connected to equipment located below. The plug 202 has a fairly long skirt with threads to form the screw connection 205. The plug is screwed against the shoulder 201. The shoulder 201 also serves as a support for a movable sealing ring 206. The ring 206 s '' presses up against the shoulder. It is pushed upwards by a helical spring 207. The helical spring is supported by a washer 208 which, in turn, is received on an elastic ring 209.

 The lower end of the tubular extension 163 has two openings, one designated by the reference number 210 and the other a lateral opening 212. The lateral opening is selectively placed in communication with the conduit 200. This connection is closed if the ring seal 206 is in the high position. The axial passage 172 opens into the lower conduit 203 via the opening 210 at the lower end.

The valve assembly shown in Figure 5 is in fact a four-way valve assembly, driven by a piston, biased by a spring. Referring to Figure 2., the reference number 203 designates the pipe which pours into the tank. This conduit is also shown in Figure 3F. It is connected to a central adapter to convert the three conduits into concentric conduits. This adapter is designated by the reference number 213 on the lower part of Figure 3F. It has three separate conduits. I1 alley them together so as to form concentric conduits. A conduit is designated by the reference number 203 which leads to an orifice 211 which, in turn, is connected to a set of small passages 212. These passages extend downwards and open into a closed hydraulic oil tank. 215. Three or four passages 212 are distributed around the converter 213.

 The pipe 200 is applied axially to the orifice 216. The orifice 216 opens onto an axial passage 217 extending through the converter 213.

The passage 217 extends along the tool, extended by the central concentric pipe 218 at the bottom of the drawing. The passage 217 thus uses the conduit 218 to extend downward. A large pipe 219 is concentric with the pipe 218. It is connected to the pipe 185. The pipe 185 leads to an orifice 220 formed in the side of the converter 213. This orifice communicates with a set of internal passages at 222, the different passages 222 meeting to introduce hydraulic oil to the exterior of the conduit 218 and the interior of the conduit 219.

 In the lower part of FIG. 3F, it will be noted that the external tubular element 102 ends and is screwed onto a hollow connector 225. The connector 225 supports the body 226 perforated in the center which, in turn, receives the converter 213. The converter 213 closes the upper end of the central connector 226. The converter 213 has the orifices for the three aforementioned conduits. The plug adapts to form a hermetic seal on different annular seals on its internal surface, thus allowing the three individual conduits to be connected to the plug. The tubular body 225 thus serves as an anchor. Because it is screwed onto the outer casing 102, it is fixed in position and constitutes a solid anchor for the constituents.

We refer to Figure 3G, the reference number 215 designates the oil tank. I1 is surrounded by an outer tubular wall 230 which extends upwards to the lower part of Figure 3F where it is welded to the connector 225. The conduit 219 passes through the center0 A sealing element is referenced 231.

This sealing element 231 is a sleeve-shaped plug which surrounds the pipe 219. The sealing element 231 has an upper annular seal 232 and a similar lower sealing ring 233. I1 has a fairly external surface. large. This outer surface is hollowed out slightly for a slight peripheral recess 234. Similar seals and a thin cup-shaped surface are on the sealing ring 231 near the internal conduit 219.

 The seal is activated by grease at high pressure. A alemite connection 236 at the lower end of a movable plunger 237 allows the lubricating grease to be introduced via the axial passage in the plunger to a chamber 238. The chamber 238 is pressurized. The plunger 237 is surrounded by a helical spring 239, and this spring pushes the plunger upward to compress the sealing grease in the chamber 238. The chamber 238 communicates through an external orifice 240.

The orifice 240 opens onto the outside of the sealing ring 231 between the annular sealing rings 232 and 233. The same lubrication is carried out on the inside adjacent to the duct 219.

The small port 240 allows the pressurized sealing grease to flow to a location between the outer seals. Hydraulic oil is stored above the sealing ring 231.

It is exposed to the drilling mud below. It is very important to prevent mud from entering the area where the hydraulic oil is located.

The sealing grease is placed in the sealing ring 231, and, by means of an adequate pressure, prevents any intrusion. Fortunately, the sealing grease is soluble in hydraulic oil. Because of this, the hydraulic oil is kept specified, while the sealing grease is kept at a higher pressure. Plunger 237 indicates whether or not additional fat is required. If the plunger is deployed indicating significant compression on the spring 239, the deployment of the plunger is read as an indication of the grease remaining in the reservoir 238. When the grease is lost slowly, the plunger 237 responds to a reduced pressure and retracts te in the sealing ring 231. Consequently, the spring 239 serves as an indicator for the grease reservoir.

The tubular member 230, centered in the outer casing 17, extends downward to additional components shown in the lower part of Figure 3G. The tubular element 219 is connected to an upper connector 244 of an intermediate connector 245. The intermediate connector 245 is screwed onto the tubular element 230. I1 has an outside diameter equal to that of the tubular element 230 which, at its turn, is equal to that of the element 102. This constitutes a smooth and uniform sectional surface on the inside of the body 17 of the drill sleeve. Here again, it should be kept in mind that the mud flows in the annular space between these elements.

 The intermediate connector 245 is a substantially tubular structure with a large wall thickness having an internal passage 246. The passage 246 is aligned with and opens into the central pipe 218. It will be recalled that the pipe 218 is located on the inside of the line 219. Line 218 thus delivers hydraulic oil under pressure in series with passage 246. Similarly, hydraulic oil flows under pressure on the outside of line 18 and on the inside of the conduit 219. A separation is obtained by the delivery of this oil under pressure to a parallel passage 247. The passage 247 is parallel to the passage 246; and both extend downward as will be described.

In Figure 3H, the tubular intermediate connector 245 is shown placed inside the body 17 of the sleeve. The mud flows however in the torus around the connector 245. The passage -247 showers in a hollow chamber above the piston 250.

The piston 250 is located axially in the center of the connector 245. The pIston 250 is received in an adjusted manner in the chamber 1 and an appr prFC annular seal around the piston prevents a leak. The piston 250 has an upwardly extending rod 252 which is placed in the passage 246. The central rod 252 is hollow. It is sealed with passage 246 by means of an appropriate annular seal. The passage 246 is in communication with an additional passage 253 opening down on the lower side of the piston 250. The piston is sealed by a seal 254. The passage 247 opens above the hermetic seal or on the upper side of the piston . The passage 253 extends to the lower side of the piston where the passage 253 branches off onto an outlet opening 255.

The lateral opening 255 is doubled in two or three places. Passage 255 introduces pressurized fluid below the piston. A room 257 is formed nearby. It is delimited by the interior of the chamber 258 of the tubular body 245. It is located below the piston head 250. It is located above a shoulder 259 of a threaded plug 260 located at the base of the tubular intermediate connector 245. The piston 250 is urged upwards by a helical spring 261. Pressurized oil which is introduced through the passage 253 flows into the chamber 257 thereby pushing the piston up to the upper end of its stroke, this being shown in Figure 3H.

 The spring 261 bears against the lower shoulder of the piston 250 and the external shoulder 259 facing upwards of the fixed threaded plug 260. The plug 260 is threaded and is screwed at 263 to the body 245.

This connection is leak proof. It is made leak tight by incorporating suitable annular seals above and below the threads.

The threaded member 260 has an alignment guide or skirt 265 which extends upwards. It is adapted to the center and positioned around the lower parts of the piston 250, this part being designated by the reference number 264. The piston comprises the plunger or rod 264 which extends below. I1 is aligned with the hollow tubular skirt 265 of the fixed lower tubular element 260. The element 260 is pierced axially by a hollow passage. The passage is centered in the upper, central skirt, 265, which surrounds the extension 264 of the piston rod. The rod-shaped extension 264, suspended from the piston 250, is axially hollow, having a central passage 267. The passage 267 is closed by a plug 268. The plug is pushed upwards by a helical spring 269. The spring is trapped by a terminal closure cap 270 which, in turn, is held in position by an elastic ring in the groove at 271. The cavity 267 is intended to receive sealing grease. This grease is delivered via a small orifice 272 in the rod 264. The grease of a high weight is introduced into the cavity 267 and seals the exterior between the elements and has its upward and downward flow. the bottom is limited by annular seals at 274 and 275. The seals
274 and 275 isolate the drilling mud from the hydraulic oil. Hydraulic oil is located above, while drilling mud is located below. The mud flows to sealing point 274.

The piston 250 is driven downwards when an appropriate pressure is applied to it via the passage 247. When it moves downwards, it compresses the spring 261. In addition, the lower end portion of the latter ci extends in the narrow throttling passage 280. The passage 280 is a limitation to the flow of drilling mud flowing through the tool. The body 260 is supported by two, three or four positioning fins 281. The positioning fins define bent passages 282 which are concentrated in the narrow passage 280. When the piston 250 is lowered, it positions the end 283 in the passage 280.The passage is substantially closed
When this occurs, a pressure pulse is generated through the measuring tool 10 and thus forms a signal which can be detected on the surface.

Referring again to Figure 5, the piston 154 goes up and down. The piston 250 in Figure 3H also goes up and down. I1 is indeed controlled by the other piston. To this end, the conduits 185 and 200 coming from the four-port multi-port valve, shown in FIG. 5, are connected so as to both move in synchronism. It is possible that they move in opposite directions, but, for the convenience of explaining the operation of the device, it is preferable that they move in the same direction. That is, when the piston 154 rises, the piston 250 rises. Therefore, conduits 185 and 200 are shown in the
Figure 2 symbolically connected so that the piston 250 is high.

Attention is now drawn to Figure 6. In this figure is shown one of the identical valves. The valves are doubled. The valves 145 and 147 in Figure 2 are identical and only their role differs. Therefore, a description of one of them will suffice. Reference numbers are generic and do not specifically refer to any particular valve. Thus, the reference numbers 145 and 147 are specific, while the numbers greater than 300 are generic.

 The reference number 300 designates a lug per particular protruding in the tubular element 132. The lug and in the form of a rounded push rod 301 when iL protrudes into the passage. I1 is rounded and relatively short0 It has a length which, when pressed by the widening 127 moving, causes a displacement of the rod 301 to the left of Figure 6. Its movement is hindered by a helical spring 302. An inlet port is provided at 303. The inlet port delivers pressurized oil to a chamber 304. The chamber is evacuated by a passage 305 through the valve body 306. The body 306 has a shoulder immediately around the inlet opening of the passage 305, and the rod 301 extends through the passage and is positioned in the immediate vicinity of the shoulder to support an element 307 of large dimensions in the form of a disc.

The disc 307 is fitted with a sealing member in one face which comes into contact with the shoulder so as to serve as a face seal. When the rod 301 is on the right when the spring 302 is pushed, a joint hermetic is maintained. When the pressure in line 303 increases, the seal becomes more effective.

 The passage 305 extends through the body 306 to an outlet pipe 308. The passage 308 is then applied to a pipe 150 which is common to five of the valves. It will be noted that the pins of adjacent valves are sufficiently spaced from one another so that only one is actuated at a time, and therefore only one valve at a time is put in communication with the pipe.

 Attention is now drawn to Figure 2 with the help of which an operating sequence will be described. The description will mainly refer to Figure 2, although some components are shown in other figures. In each case, the pressure of the mud flow against the helical spring 20 compresses it. When it is compressed, the oil which is in the tubular element 23 is pumped to the lower end and escapes through the passage 37 and into the line 50. The line 50 is connected to the reservoir 215 and in the canallsat ': on 50. The pipe 50 is connected to the tank see 215 shown in Figure 3G. This tank is at low pressure. It has a large reserve of oil under minimum pressure for the equipment.

 The line 136 in Figure 3E) is appfqude to one side of the piston 125 as shown in Figure 2.

In addition, the line 136 is also connected to the upper valve actuated by lug shown in Figure 3E, this connection being a bypass line 148 shown in Figure 3E. It is the first of the valves or upper valve, and it is a filling valve. This valve is referenced 147 in Figure 2. It is normally closed. It cannot open until the lug for this valve is actuated by displacement of the extension 127 when the piston 125 shown in FIG. 2 is pushed. When the extension 127 rises, the filling valve 147 opens from its closed position and delivers oil via a check valve and an outlet pipe 149 to fill the five transducers shown. The filling is not simultaneous but sequential. All the transducers are of identical construction. Their realization is exposed on the upper part of Figure 4.

Each is filled, by introducing hydraulic oil through the upper or terminal orifice as shown in Figure 4. When the oil is introduced, the piston shown in Figure 4 is driven down. It moves a distance determined by the closing of the small piston in the large one. The piston thus moves until the sealing ring closes, this contact being obtained between the two pistons and closing the two pistons with respect to another introduction of oil. A specified volume of oil will fill each piston if the maximum is allowed, and a predetermined portion will fill each transducer according to the measurement it performs. In FIGS. 3E and 2, the duct 50 is shown connected to the pipe 136.

 Continuing with the operation of the apparatus shown in Figure 2, each of the five transducers is filled. The filling is proportional to the signal produced by each. In the embodiment shown, oil is trapped in each transducer and is held there. She is kept there indelibly. It remains there until the enlargement 127 hits the lug for the particular valve which releases the particular transducer. As shown in Figure 2, the enlargement 127 moves in front of the different transducer valves and strikes the pins one after the other. The operation of a transducer valve is doubled in all others.

When a particular transducer valve is operated, its outlet flow is applied through the tubing shown in the
Figure 2. The line 150 is connected to the upper end of Figure 5. The oil moves the piston 154 in proportion to the time (not to the stroke) as measured by the variable. This movement is coupled thanks to the valve device represented in FIG. 5. It produces output signals in the conduits 185 and 200. These conduits extend downward through the equipment as shown in FIG. 3F, extending through the part of the equipment shown in Figure 3G and actuating the piston 250 shown in Figure 3H. This piston is slaved to piston 154.

It moves down a specified run. I1 is kept low for a period depending on the oil capacity of the transducer to code the variable by particular. This modulates the mud flow through the orifice 280. When the mud flow is modulated, a variation in flow rate and therefore pressure is formed which can be detected at the surface later.

The pston 250, being slaved to the piston 154, quickly returns to the high position shown in the drawings. This is obtained by the return of the piston 154 under the action of the hydrallliqyle thrust at high pressure to return to the high position. The piston 154 is pushed up by a spring when it is at rest.

The piston 125 moves at a controlled speed so that the lugs are struck for a time sufficient to allow the piston 250 to be fully actuated in the low or modulating position and to be returned to the high or withdrawn position.

 There is a dead time between the signals. The device uses five transducers and, therefore, generates five sequential output signals. Three are variable signals, two are calibration signals.

The calibration signals are obtained using the device shown on the upper part of the
Figure 4. Each transducer has a probe 74 which can deploy a length determined by a short, medium or long enclosure tube. This is best shown in Figures 3C and 3D, where the short calibration transducer has a relatively short case to receive the probe, length which limits its movement. The transducer 121 allows a longer stroke in comparison with the scale of the transducer 118 shown in Figure 3C.

 Finally, the enlargement 27 moves along the entire length of its trajectory. As shown in Figure 3E, the last pin encountered is that of the relief valve at the lowest point. The relief valve is also connected to line 136. Line 136 is a low pressure line. When the relief valve is open, it discharges oil from line 136 into a tank 215 at low pressure. When this occurs, the pressure in the line 136 drops significantly, and the plug 14 descends below the constriction 16.

 This is repeated cyclically, that is to say that the piston 125 is moved to the upper end of its stroke and then returned. During its return each transducer is adjusted to a new value as given for example by rotation of the magnet. This physically restores each transducer and thus makes it possible to refill it with a different quantity of oil. The cycle is repeated each time the pumps are stopped and restarted.

 The foregoing description of operation is a precise description of the operation of the tool, but is not complete since it does not describe each movement. It is believed that a better understanding is obtained by dividing the description into different descriptive parts of the operation.

With this in mind, a satisfactory starting point for the following descriptive sequence may be to focus on the upper end of the tool. It will be noted that the tool is used continuously to deliver mud as long as the pumps are in action at the head of the well. The mud flows through the drill string and through the measuring tool 10. It will be recalled that the upper end of the tool shown in the
Figure 3A has a constriction 16 which narrows the passage inside the heavy external body 17. When the pumps are in action, the spring 20 is compressed when the plug 14 is pushed down below the strangler 16. This telescopic movement downwards pressurizes the oil in the tool.The cap remains low indefinitely depending on the mud pressure. When the mud pressure is high, in combination with permanent operation the plug 14 remains low. When the pumps are stopped for any reason, the plug 14 rises
Typically, mud pumps are stopped to add another section of pipe. They could also be stopped to allow for orientation measures. In each case, the force of the fluid holding the plug 14 below the constriction 16 ends, and the spring 20 pushes the plug up. When this movement occurs, the chamber 23 is enlarged, reducing its internal pressure, and the lower reservoir 215 delivers oil under pressure. The pressure drop is also detected in the chamber 15 and in the chamber 23.

The reservoir 215 is in direct communication without throttling with the chamber 23. It does not communicate directly in this way with the chamber 15.

 When the mud pump is stopped, the plug 14 is in its lower position. Simultaneously, in each of the transducers, the piston 67 touches its closure plate 64, and the chamber 66 is reduced to zero volume. The piston 125 is in the low position (Figure 3D), and remains there until the mud pump is stopped. When it is low, the enlargement 127 which it carries is adjacent to the lug of the discharge pump, and keeps it open.

When the flow of mud stops, the spring 20 pushes the plug 14 upwards, and an oil pressure at the upper end of the tool falls below the pressure in the tank 215. This fall depends on the force spring 20 and the surface a- it registered by the sliding seal 23. When this pressure drop occurs, oil is first supplied through the line 136 through throttles and au- below the piston 125. The piston is pushed upwards. The speed of the upward movement is controlled by throttles 137 and 140. The widening 127 is driven upwards when oil is introduced below the piston 125. When it moves upwards it successively strikes each When each valve is open, oil flows from the lower reservoir 215 through the control members 151. It also flows through the check valve 170 in the piston 157, up to the line 150 through the open valve actuated by the lug and upwards through a line 60.

The small piston 72 touches the elastic ring 73 at the start of the operations, and the seal on the upper face of the piston 72 is open to flow. Oil flows down through the tube 63 (see Figure 4) in the passage 68, up through the annular cavity 69 and into the internal cavity 66 above the large piston 67. The oil delivered to the cavity 66 is at an increased pressure in comparison with the oil found in the upper chamber 15 at this instant. The differential pressure pushes the pistons 67 and 72 together downwards towards the cam 79. When the probe 74 comes into contact with the cam, the small piston 72 is stopped. The piston 67 continues its downward stroke under the pressure of the hydraulic pressure. This stroke continues until the face seal between the pistons 67 and 72 is contacted, closed and the flow is interrupted to stop the movement of the large piston. 72. It goes without saying that the valve 72 prevents flow in the opposite direction. This allows the oil to escape from the chamber or cylinder 66, but not to enter it.

After the pistons 67 and 72 have reached a stationary position with a sealing contact made, the widening 127 rises again in the tube and moves away from the lug. The special transducer valve closes and also traps the oil in the chamber 66. This oil is held in the chamber until the widening 127 again opens the valve actuated by the lug.

It will be recalled that the piston 125 is located at the lower end of the cylinder which contains it. When it moves upwards, the enlargement 127 actuates the valves actuated by lugs, and a variable quantity of oil is introduced into the transducers. The piston 125 moves to the top of its stroke to bring the enlargement 127 into contact with the lug of the filling valve. The latter allows communication with the reservoir 215 at the top of the tool. Oil then flows from the reservoir 215 without restriction until a total deployment of the plug 14 is obtained by locking contact with the shoulders 21.

At this time, the mud flow has been stopped while the measurements are made by the transducers. Each measurement is expressed by an amount of oil in the chamber 66 of the different transducers
The components of the tool take the positions shown in Figure 3. They can maintain this position for a short or long time interval depending on the duration of the sludge pump stop. When the pumps are restarted, the mud flows in front of the plug 14 and is throttled by the ring 16.

This creates a hydraulic pressure acting on the plug 14. When the mud pressure increases, the pressure inside the upper end of the tool increases. It serves as a power source to activate the tool during the sequence of operations so as to transmit signals to the surface. This increase in pressure acts on the chamber 23 to compress the spring 20 and to push the chamber down. After this has happened, the plug 14 in the adjoining tubular body also descends.

It will be recalled that the upper chamber is filled by the filling valve 147. A check valve prevents flow downwards through it. The upper chamber 15 is in communication with all the voids in the chambers in the upper end of the tool 10. Thus, it is the same extent as the chambers 48 and 122. The piston 125 moves upwards against an elastic ring, and, therefore, it is exposed in the chamber 122 to the pressure of the chamber. A movement of the plug 14 compresses the oil, increases its pressure and acts directly on the top of the piston 125. The oil in the cylinder 124 below the piston 125 is expelled from the cylinder 124 through the constriction 137. throttle delivers oil to reservoir 215. Throttle 137 controls the speed at which piston 125 moves down. Its downward travel is accompanied by the movement of the enlargement 127 which opens each of the valves assigned to the different transducers in succession. When each valve is open, the oil is in the chamber 66 where the particular transducer is pushed through the check valve 71 and in a line 60 by the oil surrounding the transducer and acting on the lower side of the pistons 67 and 72. The oil trapped in the chamber 66 passes through the open valve, the line 150, the control valve 151, the throttle 169 and then reaches the reservoir 215. When the oil flows through the throttle 169, a pressure drop occurs at the terminals of the throttle which pushes the piston 157 to compress the spring 159. The piston 157 rests on the shoulder 160. No oil circulates through the check valve 170 at this time because it only allows flow from passage 172 in line 150, but not in the opposite direction. When piston 577 moves down toward shoulder 160, seals 166 and 191 close, while seals 190 and 206 remain. This allows pressurized oil to flow into the mechanism 151 through the orifice 186. The orifice 186 opens through the seal 190 on the line 185, and oil escapes
flows to the top of piston 250. This drives piston 250 down. The oil from below the piston 250 rises through the passage 218 and the line 200. The line 200 returns to the control member 151 through the open seal 206 and into the line 203. It finally ends in tank 215.

 A downward movement of the piston 250 is accompanied by a movement of the plunger 283 which moves in the bore or passage 280. This limits the flow of mud, but does not stop it completely. The choke is enough to create a chamber pulse that travels to the surface through the column of mud flowing in the drill string.

This constitutes a tip of back pressure on the surface. The duration of the signal is linked to the amplitude of the measured variable.

 Referring to each transducer, the oil in the chamber 66 is pumped when the piston 67 moves upward to the upper closure plate 64. When this occurs, the spring 159 pushes the piston 157 toward the top against the plug 154. This pushes a small volume of oil between the piston 157 and the plug 154 until the constriction 169. This causes the seals 166 and 191 to open. Conversely, the seals 190 and 206 close.

The oil, under high pressure, penetrating into the orifice 186, flows through the line 200 to the chamber located below the piston 250, and the oil being above the piston in is eliminated to return to the reservoir 215. The piston 250 is positively driven upward by the power applied below it, and the plunger 283 is retracted from the throttled bore 280. This puts an end to the pressure pulse. The bore or constricted passage 280 delivers a total flow of mud.

Then, the widening 127 moves away from the transducer control valve which closes and hydraulically blocks the piston 67 at the upper end of its stroke against the closing element 64. The chamber 66 is reduced to its minimum capacity .

The widening 27 continues its downward stroke until it finds the relief valve at the lower end of the stroke. The relief valve was previously closed. Pressurized oil from the upper end of the tool is discharged through the discharge valve towards the reservoir 215. The plug 14 can then descend below the constriction 16. At this time, the plug 14 could be raised above the throttle when it continues its downhill course. Because it is hydraulically driven in its downward movement, the starting point for a complete deployment which results in a movement towards the throttle 16 serves as a pump delivering oil under high pressure.

Opening the relief valve lowers the pressure in the chamber at the upper end of the tool, relieves the oil pressure therein and fills the reservoir 215. The pressure in the upper end of the the tool is then equalized with the pressure prevailing in the lower end of the tool while the spring 261 maintains the piston 250 and its associated plunger 283 in the high position to avoid creating meaningless pressure pulses.

The complete operation of the tool is apparent from the above.

 Attention is now drawn to Figure 7 which is an alternative embodiment of Figure 2. The points of similarity do not require a detailed description. The points of difference are relatively obvious. The modifications result in a simpler implementation.

The duration of a pressure pulse is indicated by a flow of oil through the throttle 169 and the pressure drop across the throttle.

This pressure drop is approximately equal to the pressure difference between the oil in the tank and the high oil pressure at the top end of the tool. In order to keep the pressure drop constant during each measurement cycle, the spring 20 is incorporated into the chamber 23 which is discharged into the reservoir 215. This discharge action is accompanied by compression of the spring 20. Consequently, the compressed spring 20 has no subsequent effect on the oil pressure in the high pressure system. With this in mind the throttle 169 is converted to a flow control valve. Flow control valves are readily available which provide constant flow although the pressure drop across the valve may vary. By incorporating it, the need to isolate the influence of the spring 20 is eliminated.

Room 23 can be omitted. This can be easily achieved by simply making an orifice in the chamber 23. If this is done, the pipe 50 is then eliminated. The removal of the line 50 allows the oil to flow from the upper chamber 15 into the chamber 122, which is the area emptied into the tool itself. The structure of Figure 7 remains the same in other respects.

 The foregoing is focused on the preferred embodiment of the present invention, the scope is determined by the appended claims.

Claims (26)

1. Device for developing a signal modulated by a flow of mud, which can be installed in a drill string1 characterized in that it comprises (a) an elongated hollow external body, intended to be mounted in a train drill pipe (b) an elongated tubular internal body received inside said external body (c) organs positioning said internal body in said external body to form an annular space between said internal body and said external body, directing the flow of mud through said annular space (d) a closed hydraulic tank in said internal body and exposed to the flow of mud through said annular space (e) pressure sensitive members connected to said closed hydraulic tank to limit the pressure of hydraulic fluid in said reservoir (f) a hydraulic fluid line extending from said reservoir for delivering pressurized hydraulic fluid (g) a piston in a cylinder (h) a throttle member in said annular space which directs the flow of mud through, said throttle being located in said outer body and further directing the flow of mud down through said outer body (i) a plug extending in said constriction to vary the flow of mud allowed through said constriction, said plug being movable by said piston relative to said constriction (j) a control valve connected to said piston and to said cylinder for delivering therein controlled hydraulic fluid from said hydraulic line in order to move said piston in said cylinder (k) in a controlled manner a transducer arranged to respond to a variable and receiving hydraulic fluid and coding the variable according to an amount of fluid at least partially dependent on the variable of said transducer (1) a valve associated with said transducer for delivering fluid from said transducer to said control valve for opening it in a controlled manner; and (m) members for periodically supplying said transducer with hydraulic fluid. 2. Apparatus according to claim 1, characterized in that it comprises a spring and a piston opposing the pressure in said closed hydraulic tank.  3. Apparatus according to claim 1, characterized in that it comprises a second transducer for measuring a second variable and which operates similarly to said first transducer.  4. Apparatus according to claim 3, characterized in that it comprises members for multiplexing said valves associated with said transducers to selectively deliver a signal for said control valve first from one of said transducers and then from the other of those -this. 5. Apparatus according to claim 4, characterized in that said multiplexing members comprise a piston to which attached a rod which selectively opens and closes individual multiplexed valves connected to each of said transducers in which said valves are sufficiently spaced from each other by such so that they are individually bumped to open and close without overlapping.  6. Apparatus according to claim 5, characterized in that said piston rod is driven in a controlled manner by hydraulic fluid which is delivered to it by means of a control throttle which controls the speed of operation. 7. Apparatus according to claim 1, characterized in that said transducer comprises a piston in a cylinder, piston which moves when hydraulic fluid is introduced on one side of said piston and which is physically blocked against a subsequent movement, the range of movement indicating the variable detected by said transducer. 8. Apparatus according to claim 7, characterized in that said piston is moved in response to hydraulic fluid introduced on one of its sides and further comprising a control piston with a valve acting between said control piston and said piston to limit a displacement thereof.  9. Apparatus according to claim 7, characterized in that it comprises a protruding probe displaced by said piston, probe which protrudes dtune quantity permitted by an associated variable coding member.  10. Apparatus according to claim 9, characterized in that said probe projects against a profiled surface forming an indication of the angle of inclination of the tool.  11. Apparatus according to claim 9, characterized in that said probe protrudes against a propeller carried by a drum, said drum being driven in rotation to code said rotation of the moving drum of said probe. 12. Apparatus according to claim 9, characterized in that said probe projects against a pendulum and the movement plate thereof is determined by the position of said pendulum. 13. Device for developing a mud pressure pulse signal, device intended to be installed in a drill string, characterized in that it comprises (a) an elongated hollow external body, intended for be mounted in a drill string; (b) an elongated tubular inner body received inside said outer body (c) organs positioning said inner body in said outer body to form an annular space therebetween, directing the flow of mud through said annular space (d ) a closed hydraulic tank in said internal body (e) of the members for pressurizing the hydraulic fluid in the hydraulic tank (f) of the outlet members which are hydraulically actuated to form a mud pressure pulse when actuated (g) a regulating member for maintaining the constant pressure connected to said reservoir to act on the fluid therein so as to regulate and control the pressure of the fluid in said reservoir for operation of said outlet members. 14. Apparatus according to claim 13, characterized in that said pressure regulating member comprises a return spring and a member actuated by the mud which acts on the hydraulic fluid to apply pressure there. 15. Apparatus according to claim 13, characterized in that said pressure regulating member comprises a throttle to control the flow of hydraulic fluid from said reservoir to thereby deliver the flow at a regulated speed. 16. Simultaneous measurement drilling device, intended to be installed in a drill string for coding variables coming from the hole in order to provide information on the progress of the well, characterized in that it comprises (a) a elongated hollow external body, intended to be mounted in a drill string (b) an elongated closed instrument case, containing measuring instruments and supported by said external body (c) a closed hydraulic tank in said internal body; ; (d) members for applying pressure to the hydraulic fluid located in said hydraulic tank (e) at least two variable transducers carried by said instrument case, in which each of the transducers codes a given variable and the coding is obtained by filling in hydraulic fluid according to a volume linked to the measurement carried out by said transducer (f) a transducer outlet valve associated with each of said transducers for receiving the hydraulic fluid in said transducer; (g) an output member for developing a mud pressure pulse; and (h) multiplexing members for multiplexing selecting said outlet valve associated with said transducer for operation of said outlet member so that said transducer periodically generates a mud pressure pulse.  17. Simultaneous measurement drilling tool, intended to be installed in a drill string, characterized in that it comprises (-a) an elongated hollow external body, intended to be mounted in a drill string ; (b) an elongated closed instrument case enclosing measuring devices and supported by said outer body (c) a closed hydraulic tank in said inner body (d) at least two transducers which code variables coming from the hole, coding being obtained by delivering a quantity of hydraulic fluid varying according to the measurement of the variable obtained by said transducer (e) an output member for developing a mud pressure pulse (f) a member for preparing said transducer for operation by supplying it with hydraulic fluid, said transducer receiving a quantity of hydraulic fluid determined by measuring the variable to be coded; and (g) members for hydraulically actuating said outlet member in proportion to the hydraulic fluid received from said transducer, said transducer being periodically actuated to deliver the hydraulic fluid which it contains as a means of coding the measured variable. 18. Apparatus according to claim 17, characterized in that said transducer is filled to the extent permitted with hydraulic fluid and any excess delivered is returned to said hydraulic tank. 19. Apparatus according to claim 17, characterized in that it comprises a four-way valve, with two positions, hydraulically driven in said outlet member, valve which positions a constriction in the flow of mud through the drill string drilling.  20. A simultaneous measurement drilling rig, intended to be installed in a drill string, characterized in that it comprises (a) an elongated hollow external body; intended to be mounted in a drill string; (b) an elongated closed instrument case enclosing measuring devices and supported by said external body (c) a hydraulic tank closed in said internal body (d) a first variable transducer which codes a variable to be measured by forming a mechanical output signal; (e) an output member carried by said external body to form a mud pressure pulse in the drill string to be detected at the wellhead which codes for variables applied thereto and (f) a member for calibrating to actuate said output member for specified calibration measurements so as to define measurements in the mud pressure pulses in the drill string from said output member in contrast to signals formed by said member output from said transducer,  21. Apparatus according to claim 20, characterized in that the minimum value of the transducer is coded by a short calibration signal a and the maximum value coming from said transducer is coded by a pulse coming from said output member which is of maximum length in comparison of 1 "short calibration pulse.  22. Apparatus according to claim 20, characterized in that said outlet member comprises a throttling member selectively operable to temporarily obstruct and thus reduce the flow through the drill string to form a pulse of drilling mud in the drill string.  23. Apparatus according to claim 20, characterized in that it comprises second and third transducers for coding second and third variables  24. Simultaneous measurement drilling rig, intended to be installed in a drill string, characterized in that it comprises (a) a hydraulic reservoir closed in said apparatus for receiving and storing hydraulic fluid (b) a transducer for measuring a variable which is coded by modifying a volume in said transducer to receive a hydraulic fluid (c) means for filling said transducer to a level related to and modified by the variable to be measured by said transducer; (d) an output member attached to said apparatus for developing a mud pressure pulse in the drill string; and (e) a multiplexer for selectively actuating said transducer in a rhythmic manner to withdraw hydraulic fluid therefrom which is then conveyed to said hydraulically actuated output member to develop a mud pressure pulse in the drill string.  25. Apparatus according to claim 24, characterized in that said transducer comprises a cam which codes the angular position of the apparatus and has a range extending over 3600C.  260 Apparatus according to claim 24, characterized in that it comprises a pendulum operatively connected to said transducer for coding the angular position of the apparatus relative to the vertical so as to code the angle of the apparatus relative to the vertical .  27. Apparatus according to claim 24, characterized in that it comprises a member which references the position of the apparatus in the drill string with respect to a fixed position and which codes this position while the drill string is oriented angularly in the borehole. 28. Simultaneous measurement drilling rig, intended to be installed in a drill string, characterized in that it comprises (a) an enclosed hydraulic tank for storing hydraulic fluid under pressure (b) a transducer for coding a variable, which is actuated by coding the variable in volume of hydraulic fluid which is at least partly a function of the measurement of the variable (c) a piston which moves in a guide member over a stroke of specified length (d) a member for moving said piston at a specified speed along said guide member (e) spaced actuators along said guide member which are selectively triggered and actuated by movement of said piston in said guide member, said actuators being made and arranged to trigger an operation of said transducer; (f) an output member in said apparatus for developing a mud pressure pulse in the drill string; and (g) a member connected to said transducer for controlling said output member as a function of time with respect to the hydraulic fluid coming from said transducer so as to code the variables of said transducer in the drill string.