Method for determination of glycols and polyglycols in drilling fluid filtrates

• US 5,627,076 A
• Filed: 11/13/1995
• Issued: 05/06/1997
• Est. Priority Date: 11/13/1995
• Status: Expired due to Fees

• Current Assignee: Baker Hughes Incorporated (Baker Hughes Company)
• Original Assignee: Baker Hughes Incorporated (Baker Hughes Company)
• Inventors: Henderson, Patrick L., Walker, Nyal S.
• Primary Examiner(s): Soderquist, Arlen
• Application Number:
  US08/555,682
• Time in Patent Office: 540 Days
• Field of Search: 436/8, 436/25, 436/30, 436/60, 436/127, 436/128, 436/131, 436/164, 436/165, 436/166, 436/177, 422/104, 422/61, 422/99, 356/421-425
• US Class Current: 436/30
• CPC Class Codes: G01N 21/78 producing a change of colour
• CPC Class Codes: G01N 33/2823 raw oil, drilling fluid or polyphasic mixtures hydrocarbon content of earth materials G01N33/241; prospecting G01V; drilling per se E21B
• CPC Class Codes: Y10T 436/10 Composition for standardization, calibration, simulation, stabilization, preparation or preservation; processes of use in preparation for chemical testing
• CPC Class Codes: Y10T 436/20 Oxygen containing
• CPC Class Codes: Y10T 436/200833 Carbonyl, ether, aldehyde or ketone containing

Abstract

An apparatus and method is presented for the determination of water soluble glycols and polyglycols (polyalkoxylates). The apparatus and method are particularly suited for the on-site quantitation of glycols and polyglycols in aqueous drilling fluids.

Claims

1. A method for determining concentrations of glycols and/or polyglycols in fluids, comprising the steps of:

filtering particulates from the fluid to obtain a filtrate;

mixing an aliquot of the filtrate with a cobaltothiocyanate indicator solution to form a test solution, wherein said cobaltothiocyanate solution comprises cobalt nitrate hexahydrate, ammonium chloride, potassium thiocyanate, water and an immiscible organic solvent;

comparing the resulting color of the test solution with at least one standard cobaltothiocyanate solution to determine the concentration of glycols and/or polyglycols.

2. The method of claim 1 wherein the cobaltothiocyanate solution further comprise sodium chloride.

3. The method of claim 1 wherein said comparison step is accomplished with a reading device.

4. The method of claim 1 wherein said comparison step is accomplished with a hand-held reading device.

5. The method of claim 4 wherein said hand-held reading device comprises

an upper portion and a lower portion, said upper portion including a top surface, a bottom surface and a side surface and said lower portion including a top surface, a bottom surface, and a side surface;

connector means whereby said upper portion and said lower portion are rotatably connected;

at least one cavity located in said lower portion, said cavity being closed toward said bottom surface and open at said upper surface, said cavity being sized to allow placement of a container of standard solution therein;

at least one port placed on said side wall of said lower portion, said port opening onto said cavity located in said lower portion, such that at least a part of each container of standard solution within said cavity is visible when viewed from said side wall of said lower portion;

at least one cavity located in said upper portion, said cavity being closed toward said bottom surface and open at said upper surface, said cavity being sized to allow placement of a container of test solution therein;

at least one port placed on said side wall of said upper portion, said port opening onto said cavity located in said upper portion, such that at least the lower part of each container of test solution within said cavity is visible when viewed from said side wall of said upper portion.

6. The method of claim 4 wherein said hand-held reading device comprises:

a structure having a top surface, a bottom surface and side walls, said side walls including a front wall;

at least two cavities located adjacent to each other within said structure, said cavity being closed toward said bottom surface and open at said top surface, and said cavities sized so as to hold containers;

at least two ports, located on said front wall, placed so as to allow a view into said cavities, so that when a container is placed in said cavity, at least the bottom portion of each container is visible.