Method of scheduling propping material in hydraulic fracturing treatment

Claim 2

A hydraulic fracturing technique for generating a vertical fracture in a subterranean formation that is penetrated by a well wherein a fracturing fluid containing propping material is injected into said formation, comprising the steps of: a. determining the initial proppable fracture volume that is generated per initial incremental volume of fracturing fluid injected into said formation as a function of time; b. determining the initial amount of propping material that is required to fill said initial proppable fracture volume to a height of at least 60 percent of the height of said vertical fracture; c. iterating steps (a) and (b) for the time required to complete said hydraulic fracturing technique to determine as a function of time the amount of propping material required to fill said vertical fracture to a height of at least 60 percent of the height of said vertical fracture; and d. scheduling the propping material concentration of said fracturing fluid in accordance with the determinations of steps (a), (b), and (c).

Claim 3

In a method of generating a vertical fracture in a subterranean formation that is penetrated by a well wherein a fracturing fluid containing propping material is injected into said formation, the method of scheduling said propping material into said fracturing fluid, comprising the steps of: a. determining the initial proppable fracture volume that is generated in said formation per initial incremental volume of fracturing fluid injected into said formation in accordance with the following relationship VProp VF - V2d where VProp the proppable volume of fracture generated per incremental time, VF the volume of fracture generated, V2d the volume of fracture generated from the beginning of the treatment until the time when the fracture width at the wellbore exceeds two proppant grain diameters; b. determining the initial amount of propping material that is required to fill said initial proppable fracture volume to a height of at least 60 percent of the height of said vertical fracture; c. injecting said determined amount of propping material into said initial incremental volume of fracturing fluid injected into said fracture; and d. repeating said steps (a), (b), and (c) for subsequent incremental volumes of fracturing fluid injected.

Claim 4

In a method of generating a vertical fracture in a subterranean formation that is penetrated by a well wherein a fracturing fluid containing propping material is injected into said formation, the method of scheduling said propping material into said fracturing fluid, comprising the steps of: a. determining the initial proppable fracture volume that is generated in said formation per initial incremental volume of fracturing fluid injected into said formation in accordance with the following relationship VProp VF - V2d where VProp the proppable volume of fracture generated per incremental time, VF the volume of fracture generated, V2d the volume of fracture generated from the beginning of the treatment until the time when the fracture width at the wellbore exceeds two proppant grain diameters; b. determining the initial amount of propping material that is required to fill said initial proppable fracture volume to a height of at least 60 percent of the height of said vertical fracture; c. injecting said determined amount of propping material into said initial incremental volume of fracturing fluid injected into said fracture; and d. repeating said steps (a), (b), and (c) for subsequent incremental volumes of fracturing fluid injected.

Claim 5

The method of claim 2 wherein in step (c) said propping material concentration is determined in accordance with the following relationship:

Claim 6

In a method of generating a vertical fracture in a subterranean formation that is penetrated by a well wherein a fracturing fluid containing propping material is injected into said formation, the improvement comprising: a. injecting into said formation a first incremental volume of fracturing fluid having a first concentration of propping material to generate a first proppable fracture volume, said first concentration of propping material being sufficient to fill said first proppable fracture volume with propping material to a height of at least 60 percent of the height of said vertical fracture; b. injecting into said formation a second incremental volume of fracturing fluid having a second concentration of propping material, said second concentration of propping material being less than said first concentration of propping material; and c. injecting into said formation a third incremental volume of fracturing fluid having a third concentration of propping material, said third concentration of propping material being less than said second concentration of propping material.

Claim 7

In a method of generating a vertical fracture in a subterranean formation that is penetrated by a well wherein a fracturing fluid containing propping material is injected into said formation, the improvement comprising: a. injecting into said formation a first incremental volume of fracturing fluid having a first concentration of propping material to generate a first proppable fracture volume, said first concentration of propping material being sufficient to fill said first proppable fracture volume with propping material to a height of at least 60 percent of the height of said vertical fracture; b. injecting into said formation a second incremental volume of fracturing fluid having a second concentration of propping material, said second concentration of propping material being less than said first concentration of propping material; and c. injecting into said formation a third incremental volume of fracturing fluid having a third concentration of propping material, said third concentration of propping material being less than said second concentration of propping material.

Claim 8

The method of claim 4 further comprising injecting into said formation subsequent incremental volumes of fracturing fluid containing subsequent concentrations of propping material, each subsequent concentration of propping material being less than the next preceding subsequent concentration of propping material.

Claim 9

The method of claim 5 wherein said first, second, third, and subsequent incremental volumes of fracturing fluid are about 1000 gallons.