Abstract: A method for monitoring efficacy of removal of cuttings generated during drilling of a well is disclosed which features injection of artificial cuttings into the well-drilling fluid at a controlled rate and monitoring the rate of return of the artificial cuttings in the return drilling fluid stream. The relative rate of return with respect to the rate of injection is indicative of the efficacy of removal of the cuttings generated in the drilling process.

Abstract: In a method of tracing a well drilling mud by determining the concentration of a tracer ion in samples of filtrate from a drilling mud which contains a predetermined concentration of the tracer ion, the improvement wherein the tracer ion is the acetate ion and is present in the drilling mud in a concentration of about 1.10.sup.-3 to about 5.10.sup.-2 ions per liter.

Abstract: A drop device, method and article of manufacture used in measuring lagtime in the drilling of a well. A unique container with calcium carbide is inserted upwardly by its guide end into the open end of a pin connection prior to its threaded assembly into a lower box connection on drill pipe. The container is handled by a resilient member during placement into the pin connection and secured in place by a loop on the resilient member. The container is formed in a right cone of thin sheet material and its tapered sides are waterproof, and a disc seals the bottom or floor of the cone. The container is held in the pin connection with the floor adjacent its lower end. The pin and box connections are assembled and resumed drilling fluid flow fragments and disperses the sheet material whereby the calcium carbide converts to acetylene that is readily detected in the outflowing drilling from the well.

Abstract: In a method of tracing a well drilling mud by determining the concentration of a tracer ion in samples of filtrate from a drilling mud which contains a predetermined concentration of the tracer ion, the improvement wherein the tracer ion is the acetate ion and is present in the drilling mud in a concentration of about 1.10.sup.-3 to about 5.10.sup.-2 ions per liter.

Abstract: An apparatus (10) and method for obtaining oil and water saturation data from subterranean formations includes a drill bit (12) for boring a well core (26) containing the fluids. A core-catcher bowl (18) guides the well core (26) in the apparatus (10). An outer barrel (14) is attached to the drill bit (12) and contains the core-catcher (18). An inner liner (20) positioned in the outer barrel (14) receives the well core (26). An oil absorbent sponge-like member (22) is contained in the inner liner (20) with a diameter (24) for receiving the well core (26). The oil absorbent sponge-like member (22) absorbs the fluids contained in the well core (26).

Abstract: There is disclosed an ablatible drill comprising a soft or frangible matrix having embedded therein a multiplicity of hard inclusions which act as cutting teeth. During drilling, the matrix gradually wears away so that worn inclusions are circulated out of the hole and fresh inclusions are exposed as new cutting teeth. A plurality of joints of the ablatible drill are interconnected on the bottom of a drill string. The comminuted material of each joint of the ablatible drill provides a characteristic distinguishable from the comminuted material of adjacent joints so that in examination of the circulated returns provides an indication of which joint is then being drilled.