Wellington S Lee, 892833 Astor Dr, Norman, OK 73072

5241475, Aug 31, 1993

Oct 26, 1990

7/604670

Wellington S. Lee - Duncan OK
David E. McMechan - Marlow OK
Billy W. McDaniel - Marlow OK

Halliburton Company - Duncan OK

G01V 100

364420

An implementation of the present invention will typically be performed through use of two test fracturing or "mini-frac" operations to determine formation parameters. A first mini-frac operation will be performed to determine the fluid efficiency of the formation, and a second mini-frac operation will be performed to determine a late time fluid leak-off coefficient. The data thus obtained will be functionally related to simultaneously solve integral expressions to determine the total volume of fluid lost during pumping and the total volume of fluid lost during shut-in in response to an assumed spurt time. The fluid loss values will then be functionally related to the established fluid efficiency to estimate an early time fluid leak-off coefficient. The early time fluid leak-off coefficient thus determined will then be applied in a balance equation to verify the accuracy of such value in response to the assumed spurt time. The assumed spurt time may then be varied and the above fluid loss values iteratively reevaluated until the balance equation is satisfied within an acceptable range of tolerance.

4848461, Jul 18, 1989

Jun 24, 1988

7/211310

Wellington S. Lee - Duncan OK

Halliburton Company - Duncan OK

E21B 4326
E21B 4706
E21B 4900

166250

The invention provides a method for determining parameters of a formation and of a subsurface fracturing operation in response to the rheology of the fracturing fluid used to fracture the formation. Preferably, the fluid efficiency will be determined from pressure decline data. This established fluid efficiency will then be functionally related with indices representative of the fluid behavior and fluid consistency to determine a dimension of the created fracture. This dimension may then be utilized to determine the fluid loss coefficient of the fracturing fluid in the formation, which may then be utilized in designing a full scale fracturing treatment with provent.