US3628131A

US3628131A - Apparatus for determining salinity variations in shales

Info

Publication number: US3628131A
Application number: US15514A
Authority: US
Inventors: Harold L Overton
Original assignee: Individual
Current assignee: Individual
Priority date: 1970-03-02
Filing date: 1970-03-02
Publication date: 1971-12-14
Anticipated expiration: 1988-12-14

Abstract

An apparatus for determining salinity variations in shales, automatically or semiautomatically, to substantially continuously measure the variations of the salinity of water from different elevations in a well.

Description

,Jl I Unite States Patent [111 AM [72] Inventor Harold L. Overtoln [56] References Cited g ll87llyvgili lpermg Creelk, llllarrls County, UNITED STATES PATENTS [2|] App No E 2,330,394 9/1943 Stuart 324/30 [22] Filed g 2 1970 2,938,708 5/l960 Arps l75/50 5] a e Dec 1971 2,266,586 l2/l94l Branum 73/l53 2,749,748 6/1956 Slohod 73/153 2,692,755 l0/l954 Nowak 73/l53 [54] APPARATUS FOR DETERMINING SALHNITY Primary Examiner Michael J, Lynch VAEIIATIONS IN SHAFliJES Attorney-Pravel, Wilson & Matthews l0 laims, 1 Drawing g.

[52] US. Cl. gallgglioflgg ABSTRACT: An apparatus for determining salinity variations [5 I] Int Cl 6 27/00 in shales, automatically or semiautomatically, to substantially [50] Fieud 30. continuously measure the variations of the salinity of water M51 5 23/230 from different elevatlonsln awell.

APPARATUS FOR DETERMINING SALINITY VARIATIONS IN SI-IALES BACKGROUND OF THE INVENTION SUMMARY OF THE INVENTION The present invention relates to a new and improved apparatus for obtaining the measurements of salinity variations of water at different elevations in a well for carrying out the process of said application Ser. No. 879,147, automatically or semiautomatically, to thereby facilitate the obtaining of such measurements as the shale samples become available during the drilling ofthe well.

BRIEF DESCRIPTION OF THE DRAWING The figure of the drawing illustrates schematically the apparatus of this invention for the automatic or semiautomatic determination of salinity variations in shale cuttings obtained from different elevations in a well bore during the drilling thereof.

DESCRIPTION OF THE PREFERRED EMBODIMENT The apparatus of this invention includes a conventional rotary kiln A which is mounted on any suitable support for rotation and which is rotated by any suitable power means such as an electric motor therewith. The kiln or grinding means A is preferably divided into three sections, l1, l2 and 14. Sections I1 and 12 are separated by a wire grating 15 which has openings therethrough in the same manner as a screen or hardware cloth, preferably of about one-eighth inch in size. The

sections

12 and 14 are separated by a similar wire grating 16 which has smaller openings than the wire grating 15, and preferably the openings are approximately one-sixteenth inch in size. The final section 14 has a wire mesh screen 18, preferably of about 60 mesh so as to permit a predetermined particle size to be discharged from the grinding kiln A, as will be more evident hereinafter. Each of the sections has a plurality of grinding balls therein of different sizes, withthe section II having balls 19 of about one-half inch in diameter with section 12 having balls 21 of about one-eighth inch in diameter.

Balls

19, 20 and 21 are preferably formed of steel, but they may be formed of any other suitable material which is hard enough to accomplish a pulverizing or grinding of the shale which is introduced into the kiln A to a powder which is capable of being discharged ultimately through the screen 18. A hopper 22 of conventional construction is disposed at the upper end of the kiln A for receiving damp-washed shale cuttings in a prescribed quantity from a particular elevation in a well which is being drilled, The cuttings may come from a predetermined range within the well, and the quantity preferably is great enough for each batch which is introduced through the hopper 22 into the kiln A to provide the necessary cuttings for a series of measurements with the apparatus of this invention, as will be more evident hereinafter.

To dry the cuttings as they are being pulverized in the kiln me ype of heating means is provided in conjunction with the rotating cylinder 17, such heating means preferably being electrical heating elements 23, which surround the cylinder 17 and thereby provide relatively uniform heating for vaporizing any moisture with the cuttings as they pass through the unit A. A measuring apparatus B which includes a measuring pan 24 is disposed so as to receive the powdered shale from the kiln A. In a typical example, the batch of shale cuttings introduced at the hopper 22 from a particular elevation or range of elevation in the well being drilled may be about 200 grams, and the measuring pan 24 would be suitable for receiving about 1 gram, or maybe 10 grams, depending on the size of the other equipment being used therewith. The measuring device B is conventional in that it has a pivoted balance arm 25, with an adjustable weight 26 on one end and the measuring pan 24 on the other end. The balance bar 25 is balanced about a fulcrum 27 so that the arm 25 may tilt about the fulcrum 27 as the pivoting point, with the extent of tipping depending upon the extent of balance between the weight 26 and the pan 24 with its contents.

At the left-hand end of the balance arm 25, below the pan 24, a relay or switch 30 is disposed for engagement by a projection 25a on the arm 25. The switch 30 is normally held open by a spring or other suitable means, but when the measuring pan 24 has received a predetermined quantity of powder from the kiln A, so as to substantially balance the arm 25 on the fulcrum 27, the switch 30 is closed to activate an electrical circuit, as will be explained.

The electrical circuit which has the electrical switch or relay 30 in it includes a power source such as a battery 31, a motor 32, and an indicator light 33. Thus, when the switch 30 is closed, power is supplied to the motor 32 for operating same. The motor 32 is connected in any conventional manner to an eccentrically mounted operating rod 34 which is mounted eccentrically on a rotatable wheel or disc 35 which is schematically illustrated in the drawing. Thus, the rotation of the disc 35 causes the rod 34 to move in a circular path at its lower end and thereby to move longitudinally or vertically at its upper end. When the upper end of the rod 34 engages the lower part of the pan 24, it causes it to pivot about its pivotal mounting 240 so as to cause the left-hand end of the pan 24 to move downwardly and thereby tip the pan 24 to an inclined position, causing the powder or other contents in the pan 24 to be discharged therefrom into a hopper 35.

The hopper 35 discharges the measured quantity of the shale powder into a mixing unit C which has a tank 36 with an open upper end, and with outlet pipes 360 and 36b at its lower end. The flow of fluid out of the tank 36 through the outlet 36a is controlled by a valve 37 which preferably is electrically actuated, although it may be a manually operated valve. The outlet tube or pipe 36b is controlled by a valve 38 which'is likewise preferably electrically operated. but which may also be manually controlled.

Simultaneously, with the introduction of the powder from the measuring tray 24 into the hopper 35 and thus into the mixing unit C, water, preferably distilled water, is introduced from a reservoir 40 through an inlet tube 40a. For controlling the quantity of waterintroduced into the mixing unit C for each predetermined quantity of the shale powder, a valve 41 is disposed in the line 40a, and it is either electrically or manually controlled. For example, the valve 41 may be in the same electrical circuit with the battery 31 and may be operated when the switch 30 is closed so as to be open for discharging water into the tank 36 while the powder from the tray 24 is being dumped into the tank 36. Equal weights of water and powder are discharged into the mixing unit 36 for each measurement.

A stirring means such as stirring paddles 42 are disposed in the mixing unit C at the lower portion of the tank 36, or at any other suitable location therein, and such mixing blades 42 are electrically operated through an electrical motor 42a which is also preferably in the electrical circuit; with the battery 3! so that the rotor mixer 42 operates when the switch 30 is closed. However, the rotor 42 continues its operation for a predetermined time, so the motor 420 includes a timer for operating after it has been turned on to allow it to operate until an adequate mixing of the water and the powder has been accomplished in the unit C. It will be understood that the rotor 42 may be included in a separate circuit from the battery 31 and the switch 30 if desired, in which case the actuation of the rotor 42 may be handled by an operator when the powder and the water are being introduced into the chamber 36. Both of the

valves

37 and 38 are closed when mixing the powder and the water in the tank or chamber 36. A thermometer 36a is disposed in the tank 36 so as to obtain a temperature reading of the slurry so that suitable temperature corrections may be made in the ultimate reading if they are necessary.

To obtain a resistivity measurement of the slurry within the mixing unit C, the valve 37 is opened by the operator actuating the valve 37 orby any suitable automatic control. When the valve 37 is open, it communicates the outlet 360 with a tube 43 which leads to another tube 43a and a vacuum pump 44. A control valve 45 is provided at the end of the line 43 for a purpose to be hereinafter explained. The slurry which is drawn into the tube 43 by the operation of the vacuum pump 44 contacts the

electrodes

46a and 46b which are connected to a resistivity meter 46 of conventional construction which provides a resistivity reading for the slurry. After the sample has been drawn into the tube 43, the valve 37 is closed. Thereafter, the valve 38 is opened by the operator or by an electrical circuit automatically so as to discharge the remainder of the slurry within the mixing unit C, through the outlet 36b to a discharge tube 47. The tube 47 is connected with a three'way valve 48 which has one of its openings connected to a tube 480 leading to a source of gas under pressure such as nitrogen. The tube 48a is closed when the valve 38 is open so that the slurry passes through the valve 48 and is discharged through the line 48b into a slurry filtration cell D which includes a chamber or tank 50 with a removable cover 50a. A filter paper or other filtering device 51 is located within the chamber 50 of the cell D so that the slurry may be filtered to leave the solids on the filter paper 51 and to force the liquid or filtrate through the filter paper 51 and to force the liquid or filtrate through the filter paper 51 into a tube 52 which discharges below the filter paper 51. It should be noted that after the charge of slurry from the mixing unit C has passed into the cell D, the valve 48 is rotated electrically or manually so as to connect the pipe 480 to the source of gas under pressure such as nitrogen which then discharges its gas through the valve 48 and the line 48b to the area above the liquid slurry in the cell D. Such pressure acts to force the fluid within the slurry through the filter paper 51 so that the filtration progresses rapidly. lt willbe understood that the filter paper 51 is supported by any type of foraminous or perforated support so that the paper itself does not get forced downwardly and therefore is not ruptured during the application of the pressure thereto. After a sufi'icient pressure has developed within the cell D, the valve 48 is returned to the position shown in the drawing so as to close off the supply of pressure to the cell D. The valve 38 is closed at that point or prior thereto after having discharged its quantity of slurry and to prepare it for receiving the next measured quantity of slurry within the chamber 36.

The tube 52 leads to a vertical pipette 53 so that the filtrate passes therethrough and so that the resisitivity measurement of the filtrate can be obtained using electrodes 54a and 54b together with a conventional resistivity meter 54. Such reading is correlated with the resistivity reading of the slurry obtained at the meter 46 for each elevation for which a sample is measured and for each of the measurements for the respective elevations from which shale cutting samples are utilized in the apparatus of this invention. An electrical signal light 55 may be incorporated with the pipette 53 to indicate to the operator that there is sufficient filtrate liquid within the pipette 43 for a reading on the resistivity meter 54. The filtrate is passed from the pipette 53 to a discharge tube or pipe 56 which leads into a sodium ion potential apparatus 60 of any conventional construction. An example of such construction is illustrated in said copending application, Ser. No. 879,147. Thus, there is a reference electrode 600 and a sodium ion electrode 60b in the filtrate which serves as the electrolyte, the upper level of which is indicated at 61 in the tank 60. Such upper level 61 may be indicated by a suitable signal device 62 so that the operator will know when to take a reading on the potentiometer 65 to obtain the sodium ion potential or potential difference reading for the filtrate. The sodium ion potentiometer may have any suitable means for discharging the filtrate therefrom such as a valve 64 which again may be electrically or mechanically operated so that new filtrate samples are measured for the difierent elevations and for successive measurements at a particular elevation.

It should be noted that after each measurement of the slurry in the tube 43, it is desirable to flush such tube 43 with distilled water and for this purpose, the valve 45 may be opened, together with the valve 37 so as to wash the tube 43 with the distilled water and to remove the slurry therefrom. The water which is used for the flushing may be dumped prior to the insertion of the next quantity of powder into the tank 36, where it may be utilized as a part of such slurry since it is a relatively small amount and has a negligible effect upon the overall quantities being handled.

In addition, or in place of, the sodium ion electrode 60b, potassium ion, calcium ion and magnesium ion electrodes may be mounted inside the vessel 60 for the semiautomatic measurement of the potential differences of the filtrate with respect to such ions.

In the use or operation of the apparatus of this invention, a quantity of shale cuttings which has been obtained from a particular elevation or a range of elevation in a well which is being drilled, is initially washed and when in the damp-washed condition, such cuttings are introduced into the hopper 22. The motor 10 is operating at that time and it continues to operate so as to rotate the kiln A to pulverizc the shale cuttings to a powder which is discharged through the screen 18 onto the measuring pan or tray 24. The powder is discharged from the kiln A until a predetermined quantity is in the pan 24 so as to counterbalance the weight 26 and close the switch 30. When the switch 30 closes, the motor 10 may be stopped temporarily through any suitable electrical controls (not shown) so that further discharge of powder from the kiln A is discontinued until the pan 24 has been emptied. Alternatively, the motor 10 may continue to operate the kiln A, but the powder from the kiln A may be diverted from the pan 24 by any suitable known means.

Upon closing of the switch 30, the motor 32 operates the rotor 35 to move the operating arm 34 upwardly to cause the pan 24 to tilt about its pivot 24a and to thereby dump the measured quantity therefrom into the hopper 35 and then into the mixing unit C. Substantially simultaneously with such dumping of the powder, or at a time in close proximity thereto, water in an equal weight to the powder is discharged from the reservoir 40 into the mixing unit C where the water and the powder are mixed together with the rotating blade or rotor 42 to form a slurry. The

valves

37 and 38 are closed during such mixing operation.

The valve 37 is opened and the vacuum pump 44 is operated with the valve 45 closed so as to draw a small quantity of the slurry into the tube 43 for obtaining a resistivity measurement on the meter 46 with respect to the slurry. Thereafter, the valve 37 is closed and the vacuum pump 44 is stopped. The valve 38 is then opened, and with three-way valve 48 in the position to discharge into the cell D, the slurry flows from the tank 36 through the pipe 47 and the line 48b into the cell D. After all of the slurry has been discharged from the tank 36 into the cell D the valve 38 is closed and the valve 48 is rotated to then introduce the compressed gas from the line 48a into the cell D which facilitates the filtration through the filter paper or other filter medium 51. It should be noted that when a sufficient quantity of the solids collect on the filter paper or filter medium 51 occurs, the cell compartment or tank 50 is opened by removing the top 50a so that the solids can be discharged or removed together with the filter paper 51. The filter paper 51 would then be replaced with a clean filter paper.

The filtrate which passes through the filter paper 51 passes into the pipette 53 so that a resistivity measurement is obtained on the meter 54' for such filtrate. Also, the filtrate passes into the potentiometer tank 60 so as to obtain a measurement of the potential difference between the standard reference passes into the potentiometer tank 60 so as to obtain a measurement of the potential difference between the standard reference electrode and the sodium ion electrode. or such other electrode as may be present therein. with the filtrate serving as the electrolyte. The potential difference is indicated on the potentiometer 65. The fluid in the tank 60 is discharged through the valve 64 or is otherwise removed so as to receive the next filtrate sample for measurement: Thus, it can be seen that the apparatus of this invention provides an automatic, or semiautomatic, means for obtaining measurements with respect to the salinity conditions of water having salt therewith which is obtained from different elevations in a well. in other words. the water or filtrate which is actually measured in the pipette 53 and in the potentiometer tank 60 has salt which has been picked up from the shale by having been mixed therewith in the mixing unit C. The variations in the salinity conditions at different elevations in a well are significant as pointed out heretofore in connection with said patent application Ser. No. 879,147, and such information can be plotted with respect to the elevation in the well so as to furnish indications of overpressure areas in a well. as well as other infonnation which is of value during the drilling of a well.

The foregoing disclosure and description of the invention are illustrative and explanatory thereof, and various changes in the size. shape, and materials as well as in the details of the illustrated construction may be made without departing from the spirit of the invention.

lclaim:

1. An apparatus for substantially continuously measuring the salinity variations of shale samples from a well, comprismg:

grinding means for grinding damp-washed shale cuttings received from a well during the drilling thereof to grind said cuttings to a powder of predetermined particle size;

a measuring device disposed to receive the powder discharged from said grinding means and to measure and discharge predetermined quantities therefrom a mixing unit adapted to receive said predetermined quantities of powder discharged from said measuring device;

means for introducing a measured quantity of water into said mixing unit for each predetermined quantity of powder to form a slurry and means for discharging the slurry from the mixing unit; introduced into said mixing unit;

said mixing unit including means for mixing each measured quantity of water and predetermined quantity of powder to form a slurry and means for discharging the slurry from the mixing unit;

a slurry-filtering cell adapted to receive the slurry from said mixing unit and filter same to produce a filtrate;

means for removing said filtrate from said filtering cell; and

means for making a measurement indicative of the salinity of said filtrate.

2. The apparatus set forth in claim ll. including:

heating means with said grinding means for heating said shale cuttings as they are being ground to essentially dry same.

3. The apparatus set forth in claim ll, including:

means for drawing ofi a portion of said slurry from said mixing unit; and

means for measuring the resistivity of each said portion of the slurry withdrawn from said mixing unit.

4. The apparatus set forth in claim ll, wherein said means for making a measurement indicative of the salinity of said filtrate includes:

means for measuring the resistivity of said filtrate 5. The apparatus set forth in claim 2, wherein said means for making a measurement indicative of the salinity of said filtrate includes:

means for measuring the resistivity of said filtrate.

6. The apparatus set forth in claim U, wherein said means for making a measurement indicative of the salinity of said filtrate includes: I

means for measuring the resistivity of said filtrate; and

means for measuring the electrical potential difference between a sodium ion electrode and a reference electrode with said filtrate present as the electrolyte.

7. The apparatus set forth in claim 1, wherein:

said grinding apparatus has a final screen of approximately 60 mesh through which said powder therefrom passes; and

each said measured quantity of water and each said predetermined quantity of said powder introduced into said mixing unit are equal in weight.

8. The apparatus set forth in claim 1, wherein said grinding means comprises:

a rotatable kiln formed in a plurality of sections separated by grating having progressively smaller holes, and with each section having grinding balls therein which are progressively smaller from the inlet to the outlet thereof.

9. The apparatus set forth in claim 1, wherein said mixing unit includes:

a vessel having a stirring means therein for agitation of the liquid in the vessel; and

valve means for controlling the discharge of the slurry from said vessel. 10. The apparatus set forth in claim 1, including: means for applying fluid pressure to said slurry in said slurry filtering cell for force filtering same.

=l 4 ll= ll

Claims

2. The apparatus set forth in claim 1, including: heating means with said grinding means for heating said shale cuttings as they are being ground to essentially dry same.
3. The apparatus set forth in claim 1, including: means for drawing off a portion of said slurry from said mixing unit; and means for measuring the resistivity of each said portion of the slurry withdrawn from said mixing unit.
4. The apparatus set forth in claim 1, wherein said means for making a measurement indicative of the salinity of said filtrate includes: means for measuring the resistivity of said filtrate.
5. The apparatus set forth in claim 2, wherein said means for making a measurement indicative of the salinity of said filtrate includes: means for measuring the resistivity of said filtrate.
6. The apparatus set forth in claim 1, wherein said means for making a measurement indicative of the salinity of said filtrate includes: means for measuring the resistivity of said filtrate; and means for measuring the electrical potential difference between a sodium ion electrode and a reference electrode with said filtrate present as the electrolyte.
7. The apparatus set forth in claim 1, wherein: said grinding apparatus has a final screen of approximately 60 mesh through which said powder therefrom passes; and each said measured quantity of water and each said predetermined quantity of said powder introduced into said mixing unit are equal in weight.
8. The apparatus set forth in claim 1, wherein said grinding means comprises: a rotatable kiln formed in a plurality of sections separated by grating having progressively smaller holes, and with each section having grinding balls therein which are progressively smaller from the inlet to the outlet thereof.
9. The apparatus set forth in claim 1, wherein said mixing unit includes: a vessel having a stirring means therein for agitation of the liquid in the vessel; and valve means for controlling the discharge of the slurry from said vessel.
10. The apparatus set forth in claim 1, including: means for applying fluid pressure to said slurry in said slurry filtering cell for force filtering same.