Methods Of Forming Variable Strength Proppant Packs

Patent metadata

Field	Value
Publication number	US-2017190959-A1
Application number	US-201415314781-A
Country	US
Kind code	A1
Filing date	Sep 3, 2014
Priority date	Sep 3, 2014
Publication date	Jul 6, 2017
Grant date	—

Abstract

A variable strength proppant pack may be useful in maintaining a higher porosity and conductivity of the proppant pack over time. Forming a variable strength proppant pack may involve introducing a fluid having a composition into a subterranean formation having a fracture network therein, wherein the fluid composition changes between a plurality of compositions that comprise: a first proppant-laden fluid comprising first proppant particles, and a second proppant-laden fluid comprising second proppant particles having a crush strength greater than a crush strength of the first proppant particles; and forming a proppant pack in at least a portion of the fracture network, the proppant pack having first proppant portions comprising the first proppant particles and second proppant portions comprising the second proppant particles.

First claim

The invention claimed is:

1 . A method comprising:
continuously introducing a fluid having a composition into a subterranean formation having a fracture network therein, wherein the fluid composition changes between a plurality of compositions that comprise:
a first proppant-laden fluid comprising first proppant particles, and
a second proppant-laden fluid comprising second proppant particles having a crush strength greater than a crush strength of the first proppant particles; and
forming a proppant pack in at least a portion of the fracture network, the proppant pack having first proppant portions comprising the first proppant particles and second proppant portions comprising the second proppant particles.

2 . The method of claim 1 , wherein the plurality of compositions further comprises a proppant-free fluid, and wherein the proppant pack further includes proppant-free portions.

3 . The method of claim 2 , wherein during at least a portion of introducing the fluid into the subterranean formation the composition of the fluid changes from the first proppant-laden fluid to the proppant-free fluid.

4 . The method of claim 2 , wherein during at least a portion of introducing the fluid into the subterranean formation the composition of the fluid changes from the second proppant-laden fluid to the proppant-free fluid.

5 . The method of claim 2 , wherein changing the composition of the fluid is according to:
(A) the proppant-free fluid; (B) the first proppant-laden fluid; (C) the proppant-free fluid; (D) the second proppant-laden fluid; and (E) the (A) through (D) compositions at least once more.

6 . The method of claim 2 , wherein changing the composition of the fluid is according to:
(A) the proppant-free fluid; (B) the first proppant-laden fluid; (C) repeating the (A) and the (B) compositions at least once more; (D) the proppant-free fluid; (E) the second proppant-laden fluid; and (F) the (A) through (E) compositions at least once more.

7 . The method of claim 2 , wherein a volume of the proppant-free fluid introduced into the subterranean formation is greater than a volume of the first proppant-laden fluid introduced into the subterranean formation.

8 . The method of claim 2 , wherein a volume of the first proppant-laden fluid introduced into the subterranean formation is greater than a volume of the second proppant-laden fluid introduced into the subterranean formation.

9 . The method of claim 2 , wherein the proppant-free fluid comprises degradable particles.

10 . The method of claim 1 , wherein changing the composition of the fluid involves continuously flowing a carrier fluid and adding the first proppant particles into the carrier fluid and separately adding the second proppant particles into the carrier fluid to produce the first and second proppant-laden fluids, respectively.

11 . The method of claim 10 , wherein the carrier fluid is a proppant-free fluid and the at least two compositions further includes the proppant-free fluid.

12 . The method of claim 1 , wherein the first proppant portions of the proppant pack consist essentially of the first proppant particles and the second proppant portions of the proppant pack consist essentially of the second proppant particles.

13 . The method of claim 1 , wherein the second proppant-laden fluid further comprises the first proppant particles and the second proppant portions of the proppant pack further comprise the first proppant particles.

14 . The method of claim 13 , wherein changing the composition of the fluid involves continuously flowing the first proppant-laden fluid and metering the second proppant particles into the first proppant-laden fluid to produce the second proppant-laden fluid.

15 . The method of claim 1 , wherein at least one of the first proppant particles or the second proppant particles have a coating.

16 . The method of claim 1 , wherein at least one of the first proppant-laden fluid or the second proppant-laden fluid further comprises degradable particles.

17 . The method of claim 1 , wherein the first proppant particles have a crush strength of less than about 10,000 psi as determined by ISO 13502-2:2006.

18 . The method of claim 1 , wherein the second proppant particles have a crush strength of about 10,000 psi or greater as determined by ISO 13502-2:2006.

19 . The method of claim 1 , wherein the first proppant particles are selected from the group consisting of: sand, glass materials, nondegradable polymer materials, polytetrafluoroethylene materials, nut shell pieces, cured resinous particulates comprising nut shell pieces, seed shell pieces, cured resinous particulates comprising seed shell pieces, fruit pit pieces, cured resinous particulates comprising fruit pit pieces, wood, and composite particulates.

20 . The method of claim 1 , wherein the second proppant particles are selected from the group consisting of bauxite and ceramic materials.

21 . A method comprising:
introducing a fluid having a composition into a subterranean formation having a fracture network therein, wherein the fluid composition changes between a plurality of compositions that comprise:
a first proppant-laden fluid comprising first proppant particles having a crush strength of less than about 10,000 psi as determined by ISO 13502-2:2006,
a second proppant-laden fluid comprising second proppant particles having a crush strength of about 10,000 psi or greater as determined by ISO 13502-2:2006, and
a proppant-free fluid; and
forming a proppant pack in at least a portion of the fracture network, the proppant pack having first proppant portions comprising the first proppant particles, second proppant portions comprising the second proppant particles, and proppant-free portions.

22 . A system comprising:
a mixing system fluidly coupled to a pump via a first tubular, wherein the mixing system includes a first container containing first proppant particles or a slurry thereof, a second container containing second proppant particles or a slurry thereof, and a valve configured to alternate between (1) fluid communication from the first container to the first tubular and (2) fluid communication from the second container to the first tubular,
wherein the second proppant particles have a crush strength greater than a crush strength of the first proppant particles; and
a second tubular fluidly coupled to the pump and extending into a wellbore penetrating a subterranean formation.

Assignees

• Halliburton Energy Services Inc

Inventors

• Reddy B Raghava
• Inyang Ubong

Classifications

• E21B43/267 Primary

  reinforcing fractures by propping · CPC title

• C09K8/62

  Compositions for forming crevices or fractures · CPC title

• C09K8/805

  Coated proppants · CPC title

• C09K8/80 Primary

  Compositions for reinforcing fractures, e.g. compositions of proppants used to keep the fractures open · CPC title