delivered the opinion of the court:
The appellant filed application in the United States Patent Office for a patent upon alleged'improvements in “ Oil well drilling methods.” All the claims, 13 to 25, inclusive, were rejected by the examiner and by the Board of Appeals upon the following references:
McCulloch, 1286043, November 26, 1918.
Olsson, 1442413, January 16, 1923.
Carman, 1460788, July 3, 1923.
Lake et al., 1498045, June 17, 1924.
Kraus, 1509406, September 23, 1924.
*789Stroud, 1575944, Marcb 9, 1926.
Stroud, 1575945, March 9, 1926.
Taylor — “ The Chemistry of Colloids,” pages 5 and 6. London, Edward Arnold, 1920.
Searle — “ The Chemistry & Physics of Clays,” Ernest Benn Ltd., London, 1924, pages 246 to 249, articles entitled “ Deflocculation ” and “ Protection of Clay Suspension.”
Ibidem — page 271, article “ Increasing Plasticity ”; and
Ibidem — page 272, article “ Reducing Plasticity.”
Technical Paper No. 438, Bureau of Mines. Government Printing Office, 1928. “ Bentonite, Its Properties, Mining, Preparation, and Utilization,” page 10, Table 1. Page 11 — Article of Davis from Ind. and Eng. Chem., vol. 19, 1927, p. 1350.
California Oil Eields, January, 1923, vol. 8, No. 7, California State Mining Bureau; page 63, last sis lines.
Claims IS to 17, inclusive, and 22, are process, and tbe balance are product, claims. It is thought claims 14, 18, and 20, are fairly illustrative. These are as follows:
Claim 14. The process of increasing the efficiency of a drilling operation employing a mud-laden fluid which consists in adding to the fluid a gel-forming colloidal clay such as bentonite.
Claim 18. A mud-laden oil well circulating fluid including a gel of bentonite.
Claim 20. An oil-well fluid including a gel of bentonite carrying in suspension a heavy metal bearing mineral such as hematite, galena, barytes, etc.
Appellant’s alleged invention consists in the use of a mud in rotary deep well drilling operations, as a circulating fluid, which mud contains a colloidal suspension of bentonite and which may also carry in solution certain heavy materials, to give greater specific gravity to the circulating fluid. In drilling, this fluid is forced down through the drill pipe and drill.and then returns to the surface outside the drill pipe, carrying the cuttings from the drill. On reaching the surface, it is discharged into a settling basin, where the drill cuttings settle to the bottom, after which the fluid is drawn off and used again. It performs, in addition to carrying off the cuttings, several other useful functions. It lubricates and cools the drill, by its pressure tends to keep back gas encountered in drilling, plasters the walls of the hole and prevents caving, and helps to prevent friction and abrasion.
If there is any invention in the application of appellant, it consists in one or more of the following ideas: First, to add to a well drilling mud a colloidal material which will remain in suspension indefinitely and will not settle or precipitate out of the mud; second, to use bento-nite for such purposes; third, to add weight-increasing elements to such colloidal suspension, such as hematite, galena, etc., or to add Portland cement.
In view of the references, we are unable to discover any novelty in any of these ideas. The reference Stroud, No. 1,575,945, a patent *790issued on March 9, 1926, discloses very fully in its specification the necessity and desirability of using a well drilling mud which is “ a true suspensoid,” which will be slimy instead of abrasive, which will penetrate the wall of the well hole and build up a noneroding wall, which will lubricate, which will readily drop the well cuttings, and will have sufficient weight to resist gas pressures. To one skilled in the art of well drilling with the use of fluid mud the specification and claims of Stroud would at once suggest the desirable properties to be added to such mud.
However, it is argued that Stroud suggested the addition of a substance, barytes barium sulphate, which, it is said, will not form a colloidal suspension. Admitting, for the present, this proposition to be correct, how does the matter stand ?
If the party skilled in the art attempted to practice the art as disclosed by Stroud, and found barytes barium sulphate would not give him the colloidal suspension necessary, he would be fully advised by the publications and teachings of the prior art that bentonite might be used as such a colloid to obtain the properties taught to be ncesssary by Stroud. In the reference Technical Paper No. 438, Bureau of Mines, 1928, which refers to an article by C. W. Davis on “ The Swelling of Bentonite and Its Control,” Ind. and Eng. Chem., volume 19, 1927, page 1350, all the useful properties of bentonite as a colloid claimed in this application are discussed at length. The Davis article above referred to discusses the properties of bentonite encountered in oil-well drilling.
It seems quite obvious, therefore, that at the time appellant filed his application his conception of the use of a colloidal suspension in oil drilling mud and of the use of bentonite as such colloid did not constitute invention in view of the prior art.
The addition of loading or weight making agents, or Portland cement, was disclosed, as we view it, by the references Stroud, 1575944 and 1575945, Carman, and California Oil Fields, January, 1923, volume 8, No. 7.
We have not found it necessary to discuss the remaining references or their applicability.
The decision of the Board of Appeals is affirmed.