US3878890A — Determination of residual oil in a formation

Claim 1

Independent Claim 173 words

METHOD FOR DETERMINING THE RESIDUAL OIL IN AN OIL BEARING FORMATION PENETRATED BY THE BORE HOLE OF A WELL COMPRISING THE STEPS OF: A. LOGGING SAID FORMATION TO OBTAIN LOGGING DATA MEASUREMENTS OF THE RELATIVE QUANTITIES OF RESIDUAL OIL AND FORMATION WATER PRESENT IN THE FORMATION; B. INJECTING INTO SAID FORMATION, THROUGH SAID BORE HOLE, A SUFFICIENT AMOUNT OF AN OIL MISCIBLE SOLUTION, TO DIS SUBSTANTIALLY ALL OF THE RESIDUAL OIL IN SAID FORMATION SURROUNDING SAID BORE HOLE TO A DISTANCE EXCEEDING THE RADIUS OF INVESTIGATION OF THE LOGGING MEANS PROVIDING THE LOGGING DATA; C. INJECTING INTO SAID FORMATION THROUGH SAID BORE HOLE A SUFFICIENT AMOUNT OF WATER TO DISPLACE SUBSTANTIALLY ALL OF SAID OIL MISCIBLE SOLUTION AND CAUSE SAID FORMATION BEING TESTED TO BE SUBSTANTIALLY 100% WATER SATURATED; AND D. LOGGING FOR A SECOND TIME SAID FORMATION TO OBTAIN LOGGING DATA MEASUREMENTS; AND, E. COMPARING THE LOGGING DATA MEASUREMENTS OF SAID SECOND LOG WITH THE LOGGING DATA MEASUREMENTS OF SAID FIRST LOG TO DETERMINE THE AMOUNT OF RESIDUAL OIL IN SAID FORMATION.

Claim 2

Dependent Claim 173 words

METHOD FOR DETERMINING THE RESIDUAL OIL IN AN OIL BEARING FORMATION PENETRATED BY THE BORE HOLE OF A WELL COMPRISING THE STEPS OF: A. LOGGING SAID FORMATION TO OBTAIN LOGGING DATA MEASUREMENTS OF THE RELATIVE QUANTITIES OF RESIDUAL OIL AND FORMATION WATER PRESENT IN THE FORMATION; B. INJECTING INTO SAID FORMATION, THROUGH SAID BORE HOLE, A SUFFICIENT AMOUNT OF AN OIL MISCIBLE SOLUTION, TO DIS SUBSTANTIALLY ALL OF THE RESIDUAL OIL IN SAID FORMATION SURROUNDING SAID BORE HOLE TO A DISTANCE EXCEEDING THE RADIUS OF INVESTIGATION OF THE LOGGING MEANS PROVIDING THE LOGGING DATA; C. INJECTING INTO SAID FORMATION THROUGH SAID BORE HOLE A SUFFICIENT AMOUNT OF WATER TO DISPLACE SUBSTANTIALLY ALL OF SAID OIL MISCIBLE SOLUTION AND CAUSE SAID FORMATION BEING TESTED TO BE SUBSTANTIALLY 100% WATER SATURATED; AND D. LOGGING FOR A SECOND TIME SAID FORMATION TO OBTAIN LOGGING DATA MEASUREMENTS; AND, E. COMPARING THE LOGGING DATA MEASUREMENTS OF SAID SECOND LOG WITH THE LOGGING DATA MEASUREMENTS OF SAID FIRST LOG TO DETERMINE THE AMOUNT OF RESIDUAL OIL IN SAID FORMATION.

Claim 3

Independent Claim 174 words

A method for determining the residual oil in an oil bearing formation penetrated by the bore hole of a well comprising the steps of: a. logging said formation to obtain logging data measurements of the relative quantities of residual oil and formation water present in the formation; b. injecting into said formation, through said bore hole, a sufficient amount of an oil miscible solution, to displace substantially all of the residual oil in said formation surrounding said bore hole to a distance exceeding the radius of investigation of the logging means providing the logging data; c. injecting into said formation through said bore hole a sufficient amount of water to displace substantially all of said oil miscible solution and cause said formation being tested to be substantially 100% water saturated; and d. logging for a second time said formation to obtain logging data measurements; and, e. comparing the logging data measurements of said second log with the logging data measurements of said first log to determine the amount of residual oil in said formation.

Claim 4

Independent Claim 174 words

A method for determining the residual oil in an oil bearing formation penetrated by the bore hole of a well comprising the steps of: a. logging said formation to obtain logging data measurements of the relative quantities of residual oil and formation water present in the formation; b. injecting into said formation, through said bore hole, a sufficient amount of an oil miscible solution, to displace substantially all of the residual oil in said formation surrounding said bore hole to a distance exceeding the radius of investigation of the logging means providing the logging data; c. injecting into said formation through said bore hole a sufficient amount of water to displace substantially all of said oil miscible solution and cause said formation being tested to be substantially 100% water saturated; and d. logging for a second time said formation to obtain logging data measurements; and, e. comparing the logging data measurements of said second log with the logging data measurements of said first log to determine the amount of residual oil in said formation.

Claim 5

Dependent Claim 35 words

The method of claim 1 wherein said logging data measurements are obtained by employing a reservoir property logging means selected from the group consisting of resistivity log means, sonic log means and density log means.

Claim 6

Dependent Claim 27 words

The method of claim 1 wherein said oil miscible solution is an aqueous solution containing from about 0.5 to 60 weight percent of a surface active agent.

Claim 7

Dependent Claim 17 words

The method of claim 3 wherein said surface active agent is an overbased pale oil extract sulfonate.

Claim 8

Dependent Claim 71 words

The method of claim 1 wherein said oil miscible solution is a mixture of liquified low molecular weight hydrocarbon and water, said hydrocarbon being present in an amount of from about 3 to 15 percent of the reservoir hydrocarbon pore space and said water being in an amount such that the movement velocity of said water in said reservoir is greater than the movement velocity of said hydrocarbon in said reservoir.

Claim 9

Dependent Claim 32 words

The method of claim 1 wherein said oil miscible solution is a micellar solution and from about 3 to 20 percent pore volume of said micellar solution is injected into said formation.

Claim 10

Dependent Claim 60 words

The method of claim 1 wherein said oil miscible solution is a microemulsion forming solution and said microemulsion forming solution is an aqueous solution containing from about 15 to 60 weight percent of a polar organic compound and from about 5 to 40 percent by weight, based on the total weight of said aqueous solution, of a surface active agent.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1978-04-21	1978-10-21	1979-04-22	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1982-04-21	1982-10-21	1983-04-22	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1986-04-21	1986-10-21	1987-04-22	$7700.00	Window Closed / Lapsed

Determination of residual oil in a formation

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