Hydraulic fracturing processes for sequentially introducing differring proppant-containing fracturing fluids into subterranean formations

1 . A hydraulic fracturing process, the hydraulic fracturing process comprising:

during a time interval T 1 , pumping a first fracturing fluid comprising first coke proppant particles into a subterranean formation, such that a first weight of the first coke proppant particles, WCP 1 , is pumped into the subterranean formation, wherein at least 50 weight percent (wt %) of the first coke proppant particles have particle sizes in a range from 88 μm to 250 μm; and

during a time interval T 2 that occurs before or after T 1 , pumping a second fracturing fluid differing from the first fracturing fluid and comprising non-coke proppant particles and second coke proppant particles into the subterranean formation, such that a second weight of the second coke proppant particles, WCP 2 , is pumped into the subterranean formation;

wherein WCP 1 /WCP 2 ≥1.2.

2 . The hydraulic fracturing process of claim 1 , wherein WCP 1 /WCP 2 ≥2.0.

3 . The hydraulic fracturing process of claim 1 , wherein:

the first coke proppant particles are present in the first fracturing fluid at a concentration of CCP 1 volume percent (vol %), based on a total volume of proppant particles present in the first fracturing fluid, on a dry particle basis;

the second coke proppant particles are present in the second fracturing fluid at a concentration of CCP 2 vol %, based on a total volume of proppant particles present in the second fracturing fluid on a dry particle basis; and

CCP

⁢

1

/

CCP

⁢

2

≥

1.2

.

4 . The hydraulic fracturing process of claim 3 , wherein CCP 1 ≥60 and CCP 2 ≤20.

5 . The hydraulic fracturing process of claim 3 , wherein CCP 1 /CCP 2 ≥2.0.

6 . The hydraulic fracturing process of claim 3 , wherein CCP 1 ≥20.

7 . The hydraulic fracturing process of claim 1 , wherein the first coke proppant particles have a total concentration in the first fracturing fluid from 14 kilograms per cubic meter to 480 kilograms per cubic meter, based on the volume of the carrier fluid present in the first fracturing fluid.

8 . The hydraulic fracturing process of claim 1 , wherein the first coke proppant particles have a total concentration in the first fracturing fluid from 18 kilograms per cubic meter to 120 kilograms per cubic meter, based on the volume of the carrier fluid present in the first fracturing fluid.

9 . The hydraulic fracturing process of claim 1 , wherein the first coke proppant particles have a total concentration in the first fracturing fluid from 23 kilograms per cubic meter to 96 kilograms per cubic meter, based on the volume of the carrier fluid present in the first fracturing fluid.

10 . The hydraulic fracturing process of claim 1 , wherein the first fracturing fluid is free of non-coke proppant particles.

11 . The hydraulic fracturing process of claim 1 , wherein T 1 precedes T 2 .

12 . The hydraulic fracturing process of claim 11 , further comprising, during a time interval T 3 that occurs before T 1 , pumping a third fracturing fluid comprising non-coke proppant particles into the subterranean formation.

13 . The hydraulic fracturing process of claim 11 , wherein T 1 is a leading interval of a hydraulic fracturing operation.

14 . The hydraulic fracturing process of claim 1 , wherein T 2 precedes T 1 .

15 . The hydraulic fracturing process of claim 14 , wherein T 2 is a leading interval of a hydraulic fracturing operation.

16 . The hydraulic fracturing process of claim 14 , wherein:

a total weight of the proppant particles contained in the first fracturing fluid pumped into the subterranean formation during T 1 is WTP 1 , and

a total weight of the proppant particles contained in the second fracturing fluid pumped into the subterranean formation during T 2 is WTP 2 , and

WTP

⁢

2

≤

0.8

*

WTP

1.

17 . The hydraulic fracturing process of claim 16 , wherein WTP 2 ≤0.2*WTP 1 .

18 . The hydraulic fracturing process of claim 1 , wherein the first coke proppant particles have an apparent density of from 1.0 g/cm 3 to 2.0 g/cm 3 , and wherein the non-coke proppant particles have an apparent density of from 2.0 g/cm 3 to 3.0 g/cm 3 .

19 . The hydraulic fracturing process of claim 1 , wherein the first coke proppant particles comprise petroleum coke particles, and the non-coke proppant particles comprise sand proppant particles.

20 . The hydraulic fracturing process of claim 1 , wherein the first fracturing fluid and the second fracturing fluid comprise slickwater.

21 . The hydraulic fracturing process of claim 1 , wherein the first fracturing fluid consists essentially of slickwater and the first coke proppant particles, and the second fracturing fluid comprises of slickwater, the non-coke proppant particles, and second coke proppant particles.

22 . The hydraulic fracturing process of claim 21 , wherein the second fracturing fluid consists essentially of slickwater and the non-coke proppant particles.

23 . The hydraulic fracturing process of claim 1 , wherein the first coke proppant particles comprise fluid coke particles and/or flexicoke particles, wherein “flexicoke particles” are defined as solid concentrated carbon particles produced by a fluidized bed coking process using a reactor, a heater, and a gasifier.

24 . The hydraulic fracturing process of claim 23 , wherein the first coke proppant particles consist essentially of fluid coke particles and/or flexicoke particles.

25 . A hydraulic fracturing process, the hydraulic fracturing process comprising:

during a time interval T 1 , pumping a first fracturing fluid comprising first coke proppant particles into a subterranean formation, such that a first weight of the first coke proppant particles, WCP 1 , and a total weight of proppant particles, WTP 1 , are pumped into the subterranean formation, wherein at least 50 weight percent (wt %) of the first coke proppant particles have particle sizes from 88 μm to 250 μm; and

during a time interval T 2 that occurs before or after the time interval T 1 , pumping a second fracturing fluid comprising non-coke proppant particles and optionally second coke proppant particles into the subterranean formation, such that a second weight of the second coke proppant particles, if any, WCP 2 , and a total weight of proppant particles, WTP 2 , are pumped into the subterranean formation;

wherein:

WCP

⁢

1

/

WCP

⁢

2

≥

1.1

;

and

WCP

⁢

1

/

(

WTP

⁢

1

+

WTP

⁢

2

)

≤

0

.

5

.

26 . The hydraulic fracturing process of claim 25 , wherein WCP 1 /(WTP 1 +WTP 2 )≤0.3.

27 . The hydraulic fracturing process of claim 25 , wherein WCP 1 /WCP 2 ≥2.

28 . The hydraulic fracturing process of claim 25 , wherein T 1 precedes T 2 .

29 . The hydraulic fracturing process of claim 25 , wherein T 2 precedes T 1 .

30 . The hydraulic fracturing process of claim 29 , wherein T 2 is a leading interval of a hydraulic fracturing operation.

31 . The hydraulic fracturing process of claim 30 , wherein:

a total weight of the proppant particles contained in the first fracturing fluid pumped into the subterranean formation during T 1 is WTP 1 , and

a total weight of the proppant particles contained in the second fracturing fluid pumped into the subterranean formation during T 2 is WTP 2 , and

WTP

⁢

2

≤

0.8

*

WTP

1.

32 . The hydraulic fracturing process of claim 25 , wherein the first coke proppant particles have a total concentration in the first fracturing fluid from 14 kilograms per cubic meter to 480 kilograms per cubic meter, based on the volume of the carrier fluid present in the first fracturing fluid.

33 . The hydraulic fracturing process of claim 25 , wherein the first coke proppant particles have a total concentration in the first fracturing fluid from 18 kilograms per cubic meter to 120 kilograms per cubic meter, based on the volume of the carrier fluid present in the first fracturing fluid.

34 . The hydraulic fracturing process of claim 25 , wherein the first coke proppant particles have a total concentration in the first fracturing fluid from 23 kilograms per cubic meter to 96 kilograms per cubic meter, based on the volume of the carrier fluid present in the first fracturing fluid.

35 . The hydraulic fracturing process of claim 25 , wherein the first fracturing fluid and the second fracturing fluid comprise slickwater.

36 . A hydraulic fracturing process, the hydraulic fracturing process comprising:

during a time interval T 1 , pumping a first fracturing fluid comprising first light weight proppant (“LWP”) particles having an apparent density within a range from 1.2 g/cm 3 to 2.2 g/cm 3 into a subterranean formation, such that a first weight of the first LWP particles, WLWP 1 , is pumped into the subterranean formation, wherein at least 50 weight percent (wt %) of the first LWP particles have particle sizes from 88 μm to 250 μm; and

during a time interval T 2 that occurs before or after T 1 , pumping a second fracturing fluid differing from the first fracturing fluid and comprising non-LWP particles and second LWP particles into the subterranean formation, such that a second weight of the second LWP particles, WLWP 2 , is pumped into the subterranean formation;

wherein WLWP 1 /WLWP 2 ≥1.2.

37 . The hydraulic fracturing process of claim 36 , wherein the first fracturing fluid and the second fracturing fluid comprise slickwater.

38 . A hydraulic fracturing process, the hydraulic fracturing process comprising:

during a time interval T 1 , pumping a first fracturing fluid comprising first light weight proppant (“LWP”) particles having an apparent density in a range from 1.2 g/cm 3 to 2.2 g/cm 3 into a subterranean formation, such that a first weight of the first LWP particles, WLWP 1 , and a total weight of proppant particles, WTP 1 , are pumped into the subterranean formation, wherein at least 50 weight percent (wt %) of the first LWP particles have particle sizes from 88 μm to 250 μm; and

during a time interval T 2 that occurs before or after the time interval T 1 , pumping a second fracturing fluid comprising non-LWP particles and second LWP particles into the subterranean formation, such that a second weight of the second LWP particles, WLWP 2 , and a total weight of proppant particles, WTP 2 , are pumped into the subterranean formation;

wherein:

WCP

⁢

1

/

WCP

⁢

2

≥

1.1

;

and

WCP

⁢

1

/

(

WTP

⁢

1

+

WTP

⁢

2

)

≤

0

.

5

.

39 . The hydraulic fracturing process of claim 38 , wherein the first fracturing fluid and the second fracturing fluid comprise slickwater.