Abstract:
An apparatus and method for analyzing the continuous flow of drilling cuttings in real time on a surface while drilling employs a set of sensors placed around an analyzer tube and main auger or within the main auger related to the formation with a defined space-time shift. The method includes measuring the sample to obtain specific properties related to physical and petrophysical parameters of this formation (radiation, resistivity, inductivity, density, elasticity, others). Obtained signals are conditioned and digitized in order to derive the desired discrimination in target properties, such as rock type, porosity, density, and oil saturation. An expanding auger, with a hollow end adapted to receive a sensor tube in which the sensors or sources may be placed, is adapted to rotate or circulate a discrete media about the sensors.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation-in-part of U.S. application Ser. No. 10/711,333 filed Sep. 10, 2004 which claims the priority from U.S. application 60/481,381 filed Sep. 15, 2003 which are incorporated herein by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    During the drilling of the well, mud is circulating down-hole and brings up the formation cuttings of the strata penetrated at this time. After the lag time, which comprises of the annular velocity and the depth of the well, the cuttings arrive to the surface. Here at the surface the sample catcher devise patent U.S. Pat. No. 6,386,026 by the author, is capturing the material and at this time the apparatus and process disclosed in this invention are measuring the physical, physic-chemical and petrophysical properties of the formation. Conventionally some of the cutting sampling is done but none of previous ways are capable to eliminate the randomness, human interference errors and homogeneity of sampling. We disclose the ways to obtain continuous sampling and measuring the properties of the drilled strata. Other analyzers are incapable or unusable for this purpose. 
       BACKGROUND OF THE INVENTION 
       [0003]    During the drilling of the well, mud is circulating down-hole and brings up the formation cuttings of the strata penetrated at this time. After a lag time, which comprises of the annular velocity and the depth of the well, the cuttings arrive to the surface. Here at the surface the sample catcher such as U.S. Pat. No. 6,386,026 to Zamfes, captures the material for measuring the physical, physic-chemical and petrophysical properties of the formation. Conventionally some of the cutting sampling is done but none of previous ways are capable to eliminate the randomness, human interference errors and homogeneity of sampling. We disclose the ways to obtain continuous or semi-continuous sampling and measuring the properties of the drilled strata. Other analyzers are in capable or unusable for this purpose. 
       SUMMARY OF THE INVENTION 
       [0004]    Apparatus and method of this invention are provided for obtaining the specific properties of the drilled formation or any discrete formation moving continuously or semi-continuously. The series of sensors described below are selected to perform the data measurement and collection. 
         [0005]    The first sensor is the natural gamma rays receiver  12  (with sodium iodine crystal) on a side of analyzer tube  11 . Their Initial signal is obtained. This signal is discriminating the natural gamma radiation of different formations. 
         [0006]    The second sensor of the set is beta ray sensor  13 , placed beside the gamma on the side of main auger. This sensor will produce the beta radiation signal. 
         [0007]    The third sensor set consists of two sensors. First is the gamma ray  15  and beta ray  16  receivers attached together on one side and the weak directional beam  27  of gamma rays source  17  on opposite side of the analyzer tube  11 , will produce the dual signal synchronously reflecting the absorption radiation  21  and induced radiation  16  properties of media passing inside the tube. 
         [0008]    The fourth sensor of the set is the Induction coil  34 , with directional ferrous insert  33  this way that the magnetic field  38  is passing through the material  37  in the analyzer tube. Different formations will produce a different signal  36 . 
         [0009]    The fifth sensor of the set consists of Sonic source  42  on one side and the two receivers  43  and  44  on the opposite side; the signals obtained will be reflecting the formations properties. 
         [0010]    The sixth sensor set consists of injector of dissolvent  55 , which is constantly injecting small dose of dissolvent fluid into the cuttings flow and Fluorescent brightness measurement sensor  54 , which measures the amplitude and frequency of light emission produced versus time. 
         [0011]    For further processing the information collected is passed to the CPU. In the CPU the special algorithms that allow to obtain required physical, physic-chemical and petrophysical parameters. 
         [0012]    In an alternative embodiment, the sensors and/or sources may be mounted within the analyzer tube (rather than externally). The method and apparatus described here may be added to the previously described auger which provides the capability to process the cuttings in circular motion around a hollow part of the auger in which the sensors and/or sources may be mounted. 
         [0013]    The hollow and increased diameter parts of the auger axis is one part of the auger that continuously spins the cuttings around the unmovable sensor tube with gamma ray and gamma spectrograph sensors. That is, the auger shaft  1 . 2  is rotatably operated by drive means, such as an electric motor  1 . 6  to rotate the auger  1 . 7 /auger shaft  1 . 2  relative to the analyzer tube  11 . However, the hollow part or void  1 . 4  provides a void or space adapted for receiving a fixed or unmovable sensor tube  1 . 5  with any of the above sensors. The advantage of having the discreet media moving around the sensor is an improved signal to noise ratio which improves the useful signal for further measurement of drill cutting properties as apparent gamma, gamma spectrograph and neutron density porosity. As one ordinarily skilled in the art recognizes, a variety of other information can be obtained from the above sensors. 
         [0014]    In a first aspect, the present invention provides an apparatus for measuring signals in discrete media of drilling cuttings including at least one sensor placed proximate an analyzer tube for analysis of the drilling cuttings; and an auger within the analyzer tube for conveying the drilling cuttings through the analyzer tube, past the at least one sensor. 
         [0015]    Preferably, the at least one sensor including a natural gamma radiation sensor; a natural beta radiation sensor; a sensor for measuring the absorption properties of gamma radiation; a sensor for measuring the absorption properties of beta radiation; and a sensor for measuring the sonic velocities and penetration properties. Preferably, the apparatus is adapted to convey the drilling cuttings through the analyzer tube, past the at least one sensor, in the order a, b, c, d, e. Preferably, the sensor for measuring the absorption properties of gamma radiation (and beta radiation) comprising a gamma ray sensor ( 15 ) and a beta ray receiver ( 16 ) proximate one another on a side of the analyzer tube. Preferably, the at least one sensor further comprises a sensor for measuring the resistivity. Preferably, the sensor for measuring resistivity is a contact sensor. Preferably, the sensor for measuring resistivity is an induction sensor. Preferably, the induction sensor includes a source coil, proximate the drilling cuttings, the electrical coil adapted to receive an alternating electrical current; and a receiver coil adapted to detect electrical current induced in the receiver coil by the source coil. Preferably, the analyzer tube is a plastic tube. Preferably, the auger is made of non-conductive materials. Preferably, the apparatus further includes injection means for injecting a dissolvent ( 55 ) into the drilling cuttings; and a fluorescence brightness measurement sensor for measuring the amplitude and frequency of light emission produced. 
         [0016]    In a further aspect, the present invention provides a method of analyzing drilling cuttings including providing at least one sensor placed proximate an analyzer tube for analysis of the drilling cuttings; and an auger within the analyzer tube for conveying the drilling cuttings through the analyzer tube, past the at least one sensor; receiving the drilling cuttings from a subsurface formation; conveying the drilling cuttings through the analyzer tube, past the at least one sensor; recording readings from the at least one sensor; and correlating the readings to the subsurface formation. 
         [0017]    Preferably, the method further includes injecting small dose of dissolvent into the drilling cuttings and measuring the fluorescent brightness of the drilling cuttings containing the small dose of dissolvent. 
         [0018]    In a further aspect, the present invention provides an apparatus for logging the properties of a discrete media, including a rotatable auger, having a generally central auger shaft, the auger shaft having at least a portion having a central void, the void adapted to receive a sensor; and an analyzer tube for containing the auger and the discrete media, wherein the auger is adapted to rotate the discrete media about the sensor. 
         [0019]    Preferably, the sensor is rotationally fixed relative to the analyzer tube. Preferably, there is relative rotational movement between the sensor and the auger shaft. Preferably, the sensor is fixed and the shaft rotates. Preferably, the shaft rotates in a first direction and the sensor rotates in a second direction, the second direction opposite the first direction. Preferably, the auger is further adapted to convey the discrete media axially along the generally central shaft. 
         [0020]    In a further aspect, the present invention provides a method of logging a property of a discrete media, including providing at least one sensor for determining the property of the discrete media; and providing relative movement of the discrete media about the sensor. 
         [0021]    Preferably, the discrete media is cuttings from a drilling operation. 
         [0022]    In a further aspect, the present invention provides a method to correlate the quantity of sample passing through an auger, comprising correlating the relative deflections depending on quantity of sample passing through the auger. 
         [0023]    Other aspects and features of the present invention will become apparent to those ordinarily skilled in the art upon review of the following description of specific embodiments of the invention in conjunction with the accompanying figures. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0024]    Embodiments of the present invention will now be described, by way of example only, with reference to the attached figures, wherein: 
           [0025]      FIG. 1  is a schematic of an auger and analyzer tube and the sensors placed externally around it; 
           [0026]      FIG. 2  is a schematic of the gamma absorption apparatus where a directionally restricted gamma beam is used as a source; 
           [0027]      FIG. 3  is a schematic of an induction sensor placed on the analyzer tube. The body and the screws are made from plastic to eliminate the induction currents; 
           [0028]      FIG. 4  is a schematic of the sonic sensor placed on the analyzer tube and includes a source and a plurality of receivers; 
           [0029]      FIG. 5  is a schematic of a fluorescence sensor on the analyzer tube including a dissolvent injector and a fluorescent light emission sensor for analyzing the amplitude and frequency of light emission; 
           [0030]      FIG. 6  is a schematic of a directionally restricted gamma source into the beam of gamma rays; 
           [0031]      FIG. 7  is an apparatus having an auger having an interval void or space within an expanded portion to receive a sensor tube housing the one or more sensors; 
           [0032]      FIG. 8  is a simplified schematic of a cross section of the analyzer tube of  FIG. 7 ; and 
           [0033]      FIG. 9  is a simplified schematic of an induced resistivity sensor utilizing electrical transformer principle. 
       
    
    
     DETAILED DESCRIPTION 
       [0034]    A first sensor is a natural gamma rays receiver  12  (with sodium iodine crystal) on a side of analyzer tube  11  the initial signal is obtained. This signal is discriminating the natural gamma radiation of different formations. 
         [0035]    A second sensor of the set is beta ray sensor  13 , placed beside the gamma on the side of main auger. This sensor will produce the beta radiation signal measurement. 
         [0036]    A third sensor set consists of two sensors. First is the gamma ray  15  and beta ray  16  receivers attached together on one side and the weak directional beams  27  of gamma rays source  17  on opposite side of the analyzer tube  11 , This set will produce the dual signal synchronously reflecting the absorption radiation  21  and induced radiation  16  properties of media passing inside the tube. 
         [0037]    A fourth sensor of the set is the Induction coil  34 , with directional ferrous insert  33 . This way that the magnetic field  38  is passing through the material  37  in the analyzer tube. Different formations will produce different signal  36 . 
         [0038]    A fifth sensor of the set consist of mass quantity  14  ( FIG. 1 ) or Sonic source  42  on one side and the 2 receivers  43  and  44  on opposite side ( FIG. 4 ), the signals obtained will be reflecting the formations&#39; properties. 
         [0039]    A sixth sensor set is consist of injector of dissolvent  55 , which is constantly injecting small dose of dissolvent into the cuttings flow and Fluorescence brightness measurement sensor  54 , which measures the amplitude and frequency of light emission produced. Preferably, the sample flows in a direction  18  or direction of movement  52 , motivated by auger  22 . The auger  22  may have an auger axis  53 , such as metal axis  25  ( FIG. 2 ) or a plastic axis  32  ( FIG. 3 ). The body of analyzer tube  51  may be plastic (e.g. plastic tube  41 ) and the auger  22  may be plastic, for example plastic auger  45 . Referring to  FIG. 6 , the drilling cuttings may flow in a plastic tube  61  along axis  62 . A source  65  gives off gamma ray beams  66  which pass through the drilling cuttings to a gamma/beta sensor  68 . A lead directional restrictor  64  directs the gamma ray beams  66 . Lead cover  67  and lead protection cover  63  protect nearby users from the gamma ray beams  66  and reduce the background gamma ray beams  66  to reduce background noise. 
         [0040]    In operation, a combination of methods may be used to obtain specific measurement from combination of sensors described above. This combination of measurements data related to the same material sample is further processed to solve the required problem or obtain the basic physical and petrophysical properties. 
         [0041]    The method includes: 
         [0042]    A first method (Natural Gamma) consists of obtaining the natural gamma radiation properties of substrata formations through measuring the drilling cuttings flow by means of gamma rays receiver  12 . Shielded by lead shield  19  from external radiation background the sensor is measuring the radiation of specific formation. These properties are factor of composition of the formation and this information is used for further processing. 
         [0043]    A second method (Natural Beta) consists of obtaining the natural gamma radiation properties of substrata formations through measuring the drilling cuttings flow by means of beta rays receiver  13 . The shielded by lead shield  19  from external radiation background the sensor is measuring the radiation of specific formation. These properties are factor of composition of the formation and this information is used for further oil and gas industry. 
         [0044]    A third process (Sonic) consists of obtaining the travel time from source  42  to sensors  43  and  44  and then differential signal of the two measurements is obtained. This parameters may be used in characterization of substrata formations through measuring the drilling cuttings flow. The parameters related to Density, Grain size, Porosity and other can be related; and the parameter to correlate the quantity of sample passing at this time through the auger. 
         [0045]    The related deflections depending on quantity will be explained. 
         [0046]    A fourth method (Absorption Gamma) consists in obtaining the measurement of gamma radiation emitted by the source  17  or  24  passed through the formation and received on gamma sensor  15 . This measurement reflects the properties of substrata formations through measuring the drilling cuttings flow by means of Absorption of Gamma rays. The shielded by lead shield  19  from external radiation background the sensor is measuring the radiation of specific formation. These properties are factor of composition of the formation and this information is used for further processing. 
         [0047]    A fifth method (Induced Gamma-Beta) consists in obtaining the measurement of gamma-beta radiation induced by the source  17  or  24  and measured by sensor  16 . This measurement reflects the properties of substrata formations through measuring the drilling cuttings flow by means of induced radiation of Gamma-Beta rays. The shielded by lead shield  19  from external radiation background the sensor is measuring the radiation of specific formation. The properties are the factor of composition of the formation and this information is used for further processing. 
         [0048]    A sixth method (Inductivity) consists in calculation of Inductivity by measuring flow current  36  produced by source  35  through coil  34 . The magnetic field  38  created between Ferrous magnetic embodiments  33  is passing through the drilling cuttings  37  in plastic tube  31 . This measurement reflects the electrical resistivity properties of substrata formations through measuring the drilling cuttings flow. The properties are factor of composition of the formation and this information is used for further processing. 
         [0049]    A seventh method (Fluorescent Brightness) consists in obtaining the measurement of Fluorescence brightness amplitude and frequency and builds the histogram of two parameters Amplitude versus Time. The process consists of injecting of dissolvent fluid  55 , in small dose, continuously, in the formation. If the formation contained hydrocarbons Fluorescence light emission will be generated. Fluorescence brightness measurement sensor  54 , which measures the amplitude and frequency of light emission produced. Time factor in measurements can be obtained in similar process disclosed by author in U.S. Pat. No. 6,715,347. The measurement reflects the hydrocarbon type, presence and saturating properties of substrata formations through measuring the drilling cuttings flow. The properties are the factor of composition of the formation and this information is used for further processing. 
         [0050]    An eighth method (algorithm for calculation of basic formation properties) includes of: 
         [0051]    Creating the database for real time measurements. 
         [0052]    Analyze the physical properties that relate to the same point of measurement. 
         [0053]    Analyze the uninfluenced measurements, as self gamma radiation, induction. 
         [0054]    Analyze the influenced measurements, as induced by source gamma radiation absorption and emission, induction of fluorescence by injecting dissolvent fluid. 
         [0055]    Analyze the information on known formation with calibrated properties. 
         [0056]    Combine the post-drilling open hole logging information for deriving the relative calculations for measurements obtained at the surface. 
         [0057]    Referring to  FIGS. 7-8 , the above sensors, rather than being mounted on the exterior of the analyzer tube, may be located within the analyzer tube, for example within the auger, preferably within a removable sensor tube that may be readily inserted or removed into a void or space within the auger. 
         [0058]    In one such arrangement, drilling cuttings are discharged (e.g. from a mini-shaker) to an auger  22  at an enlarged end (e.g. past the 1.3 position). The drilling cuttings then are conveyed by rotating motion along the auger  22  and around it. This rotation exposes the drilling cuttings around the sensors (e.g. in the unmovable sensor tube  1 . 5  in the hollow part or void  1 . 4 ) for a longer time thus increasing the signal measured and increasing the signal to noise ratio. The outside part of the analyzer tube  11  may be covered by lead shield or other shielding for preventing or reducing ground radiation and/or background radiation to affect the measured signal. 
         [0059]    The hollow and enlarged diameter part of auger axis is one part of the auger  22  that continuously rotates the cuttings around the unmovable sensor tube with one or more of the sensors above. The increase in diameter is adapted to provide the hollow part or void  1 . 4  for placing the unmovable sensor tube  1 . 5  with one or more of the sensors (or sources) above. One advantage of having the discreet media moving around the sensor or sensors or hollow part provides increased signal to noise ratio, which improves the useful signal for further measurement of drill cuttings properties. As recognized by one skilled in the art, a variety of other information can be obtained from the above sensors. In addition, a variety of other sensors may be placed in the hollow part or void  1 . 4 , for example within the unmovable sensor tube  1 . 5 . 
         [0060]    While shown with the sensors within the sensor tube  1 . 5  within a hollow part or void  1 . 4  within the auger  22 , optionally the source (for example gamma or sonic velocity). 
         [0061]    Referring to  FIG. 9 , one or more source coils  100  are proximate the analyzer tube  11 . An AC source  110  provides current to the one or more source coils  100 . The AC source  110  is preferably in the frequency 50-20,000 Hz. A receiver coil  120  may be located within a sensor tube  1 . 5  (with or without one or more of the above sensors). Any current induced in the receiver coil  120  is measured. 
         [0062]    Optionally, a representative sample of the drilling cuttings may be collected and stored for further analysis. Preferably, a digital wheel such the vane-type dosing or metering device as described in U.S. Pat. No. 6,836,026 may be used to collect small (e.g. 4 or 5 gram) samples. In doing so, the continuous or semi-continuous analysis of the present invention is brought full circle from the drilling cuttings from the formation drilled, through continuous or semi-continuous analysis, and to manageable discrete representative physical samples, those representative samples physically matching the formation drilled and analyzed. 
         [0063]    While described as applicable to analysis of drilling cuttings, the present invention is applicable to other discrete media. 
         [0064]    In the preceding description, for purposes of explanation, numerous details are set forth in order to provide a thorough understanding of the embodiments of the invention. However, it will be apparent to one skilled in the art that these specific details are not required in order to practice the invention. 
         [0065]    The above-described embodiments of the invention are intended to be examples only. Alterations, modifications and variations can be effected to the particular embodiments by those of skill in the art without departing from the scope of the invention, which is defined solely by the claims appended hereto.