Патент USA US3451270код для вставки
June 24, 1969 A_ p, Rmx-WER»l JR" El’ AL 3,451,263 LOGGING WHILE DRILLING SYSTEM Filed Nov. 29, 1967 Shee‘lfl Za. / of2 June 24, 1969 3,451,263 A. P. RICHTER,4 JRu ETAL LOGGING WHILE DRILLING SYSTEM Sheet Filed Nov. 29, 1967 2 ___.. of2 . ?'MlJw-THC'LC. i l 1 f v4 p United States Patent O ” ICC 3,451,263 Patented June 24, 1969 1 2 3,451,263 uring surge pressure of drilling mud in an earth bore hole as the drill string is being run down into the mud LOGGING WHILE DRILLING SYSTEM Albert P. Richter, Jr., and James D. Bruner, Houston, Tex., assignors to Texaco Inc., New York, N.Y., a corporation of Delaware Filed Nov. Z9, 1967, Ser. No. 686,566 Int. Cl. E211) 29/00 U.S. 'CL 73-152 iilled borehole. The sensor actuates a remotely located transducer. Electrical signals representative of the surge pressure beneath the bit are transmitted to a transducer signal processing circuitry unit and then to a recording unit, said units being incorporated in the drill string above I 3 `Claims ABSTRACT OF THE DISCLOSURE Apparatus for continuously measuring the surge pres~ the drill bit. Other objects and advantages as well as the various fea 10 tures of novelty which characterize the invention are pointed out with particularity in the claims annexed here with and forming part of the specification. For a clearer sure developed when a drill string having a drill bit at the end thereof is run into an earth borehole ñlled with drill understanding of the invention, its operating advantages surge pressure are transmitted from the pressure trans Brief description of the drawings and the specific objects attained by its use, reference is to ing mud. Incorporated in the drill bit per se isA ra? pressure 15 be had to the accompanying drawing ñgures and descrip tive matter in which there is illustrated and described an sensing element which actuates a'?ëfñ'öt'ëly located pres illustrative embodiment and practice of the invention. sure transducer. Electrical signals representative of the ducer to a transducer signal pocessing circuitry unit and FIG. 1 is an elevation View showing a rotary drilling then to a recording unit, said units being incorporated in 20 apparatus as it is being lowered back into an earth bore the drill string above the drill bit. hole filled with drilling mud; said apparatus including the surge pressure measuring apparatus in accordance with the present invention. Background of the invention FIGS. 2a, 2b and 2c are cross-sectional elevation views 25 of different sections of the lower end of the drilling appa This invention pertains in general to a method and ratus of FIG. l and including the rotary drill bit of the apparatus for detecting, measuring and recording the apparatus; FIG. 2a showing the uppermost section, FIG. surge pressure below a drill bit at the end of a drill 2b the next lower section, and FIG. 2c the lowermost sec string as the drill string is run downwardly into an earth tion below that of FIG. 2b. 30 borehole filled with drilling mud or ñuid. One important parameter in connection with the mak Detailed description of the invention ing of a borehole in the earth for the purpose of seeking In the drawing figures like elements or components are subsurface oil, gas or minerals is the magnitude of the designated by the same reference numbers throughout. surge pressure below the drill bit. While the borehole is In FIG. l there is illustrated a drill string designated being made in the earth by a rotating drill bit, the bore hole has drilling mud circulating therein. However, from generally by the reference number 10, which drill string changed. Upon lowering the drill string back into the mud into an earth borehole 14 which traverses various earth is made up of, among other things, a series of drill pipes time to time, for various reasons, the rotation of the coupled end-to-end. Located at the lowermost end of drill drill bit is stopped and the circulation of the drilling mud is also stopped in order to raise the drill string, hav 40 string 10 is a conventional rotary drill bit designated, gen erally, by the reference number 12. As suggested in FIG. ing the drill bit at the end thereof, out of the borehole. 1, drill bit 12 at the end of the drill string is being lowered For example, it may be that the drill bit has to be formations and the borehole 14 is ñlled with drilling mud filled borehole it often happens that the drill string is dropped rapidly through an appreciable distance and there 45 or -drilling fluid. The drilling mud being designated gen erally by the reference number 14a. As shown in FIG. 1 occurs immediately below the drill bit a rather high surge the drill bit and drill string, although well down in the pressure. This surge pressure is comprised of among mud ñlled borehole, have not as yet reached the bottom others three components; one, the pressure produced by thereof. the bit acting as a piston in the borehole; two, the pressure Referring now to FIG. 2a there shown is a capsule required to get the mud displaced by the drill string into 50 designated generally by the reference number 16. As in motion; and, three, the pressure necessary to overcome dicated `by the label, capsule 16 houses a recording unit the viscous drag of the mud column. If these components and associated circuitry. Capsule 16 is a sealed container of pressure are high enough, damage to the surrounding adapted to withstand pressures of about 14,000 lbs. per formations would result and would possibly fracture the formation with the consequent loss of circulation of the 55 square inch, or more as required. As shown recorder cap sule 16 is mounted coaxially within a special sub 18 which drilling mud. In some cases the pressure that will fracture a formation is very near the pressure produced by the mud weight necessary to prevent a blowout. In such cases, the surge pressure is a critical item indeed. Hence, it is desirable to measure the magnitude of the surge pressure. 60 Summary of the invention is a conventional drill collar that has been hollowed out for the purpose of receiving capsule 16. Capsule 16 is sup ported within special sub 18 by means of a plurality of longitudinal members 20 or runners which are welded to the outside surface of capsule 116 along substantially the entire length thereof and to the special sub 18. Capsule 16 is closed at its upper and lower ends by two end caps One object of the invention is to provide a method and 22 and 24, respectively, or -bull plugs as they are often apparatus for determining the surge pressure below a called. Details of the construction of capsule 16 are dis~ drill bit. 65 closed in more detail in U.S. patent application Ser. No. Another object of the invention is to prevent forma 674,335 entitled “Logging While Drilling System” filed tion fracturing and loss of circulation of the drilling mud Oct. 10, 1967 in behalf of Albert P. Richter, Jr. and while running the drill string into a mud filled borehole James D. Bruner. As indicated in FIG. 2a, end cap 24 in the earth. has a threaded aperture therethrough which receives a In accordance with an illustrative embodiment and 70 threaded conduit 26. The conduit 26 has an annular practice of the invention there is incorporated in a drill groove formed on the outside surface thereof and this bit at the end of a drill string a pressure sensor for meas~ groove contains a. sealing O‘-ring 28. 4 Coupled to the lower end of the special sub 18 by this force to the transducer 56. Transducer 56 may, for example, include a strain gauge conñguration. The sig nals from the transducer 56, which are representative of the surge pressure transmitted through the oil filled col means of conventional API tool thread is another special sub 30. Mounted coaxially within special sub 30 is an other sealed capsule 32 similar to capsule 16. Capsule 32 as indicated by the labeling contains transducer signal umn 54, are thence transmitted via the conductors 58 to capsule 32 and thence in the manner hereinbefore ex processing circuitry. Capsule 32 is mounted on welded runners 34 to the special sub 30 in the same manner as plained to the capsule 16 whereat they are recorded. Thus as the drill string and bit are passed downwardly through the mud lilled borehole there is obtained simultaneously capsule 16 is mounted by means of the runners 20 to the special sub 18. Capsule 32 is provided with two end caps 3‘6 and 38 or bull plugs, the end caps 36 and 38 being 10 a record of the surge pressure below the drill bit corre at the upper and lower ends of capsule 32. More details lated with the velocity and depth of the drill bit in the on the construction and arrangement of capsule 32 is dis borehole. The velocity being recorded by means of the re closed in the aforementioned U.S. patent application Ser. c-order 60. Recorder `60 shown in FIG. 1 is a velocity No. 674,335. measuring device for the purpose of measuring how fast End cap 36 as shown in FIG. 2b has an aperture there 15 drill string 10 is advancing downwardly into borehole 14. through which receives the conduit 26. Conduit 26 carries While a specific embodiment and practice of the inven therewithin electrical conductors 42, which conductors tion has been shown and described in detail to illustrate transmit signals from the transducer signal processing cir cuitry -within capsule 32 to the capsule 16 which contains a recording unit such as a magnetic tape recorder and as the application of the principles of the invention, it is to be understood that the invention may be embodied other 20 sociated circuitry. As shown in FIG. 2b end cap 38 has a threaded aperture therethrough which receives the end wise without departing from such principles. What is claimed is: 1. Apparatus for logging at least one parameter deter mined in a earth borehole containing drilling mud com of a threaded oil-filled conduit 44. At the point where prisingz' conduit 44 enters the aperture in end cap 38 a pair of annular grooves is provided in the outside surface of the 25 a drill string having a drill bit at an end thereof; conduit and these grooves receive the sealing O-rings 46. means in said drill bit for detecting at least one param Coupled by means of conventional API tool threads at eter in the borehole; the end of special sub 30 is another special sub 48. Cou means in said drill string for recording the detected pled to the lowermost end, as shown in FIG. 2c, of specal parameter; sub 48 is the drill bit 12. As shown in FIGS. 2b and 2c 30 said detecting means in said drill bit detecting surge conduit 44 extends coaxially within special sub 48 from pressures below the bit as the drill string and bit are end cap 46 through special sub 48 to the drill bit 12. Drill passed into the mud containing earth borehole. bit 12 'has a central opening formed therein for receiving 2. Apparatus for logging surge pressure below a drill conduit 44. An annular space is formed in the drill bit bit at the end of a drill string as the string yand bit are for receiving an `O-ring seal 50. .At the lowermost end of 35 passed into an earth Áborehole containing drilling mud conduit 44 there is mounted a pressure sensing element, comprising: a pressure sensing device incorporated in the or sensor, 52. Pressure sensor 52 may, for example, be a drill bit and located in the bit so as to sense the surge diaphragm or piston type of pressure transmitting ele pressure of «the ‘drilling mud as the bit passes through the ment. Conduit 44 is ñlled with oil column 54. The oil drilling mud in the borehole; housing means mounted in column 54 ñlls the entire hollow in_ner passage of conduit 40 the drill string and including therein a transducer for con 44 from the element 52 in the drill bit at one end to a verting pressure energy to electrical signals, circuitry for pressure transducer 56 located at the other end mounted processing the electrical signals and a recording unit for in the end cap 38. Coupled to the pressure transducer 56 recording the signals; and, means for transmitting pressure in end cap 38 are the electrical conductors 58 which sensed by said device to the transducer. transmit electrical signals from transducer 56 to the trans 45 3. Apparatus according to claim 2 wherein the pressure ducer signal processing circuitry. Signals from the trans duoer signal processing circuitry in capsule 32 are then transmitted via the conductors 42 through conduit 26 to the capsule 16 to the recording unit and associated cir cuitry. With the apparatus, shown more particularly at 50 FIG. 2c, the ‘determination of surge pressure of the drill ing mud below the bit as the drill string 10 and bit 12 are being lowered into borehole 14 may be determined by the following method: As the drill string and bit are lowered into the bore hole and traverses various earth formations thereof, the pressure sensing element 52 is actuated by the surge pres sure of the drilling mud. The element 52 transmits this force to the oil ñlled column 54 which, in turn, transmits 55 sensing device includes a piston, and wherein the last mentioned means is a lluid-ñlled conduit extending from the piston to the transducer. References Cited UNITED STATES PATENTS 2,925,251 3,203,243 3,374,341 2/1960Í 8/1965 3/1968 Arps _____________ __ 175-39 Lyles ___________ __ 73~l52 X Klotz ___________ _.. 175-48 X RICHARD C. QUEISSER, Primary Examiner. JERRY W. MYRACLE, Assistant Examiner.