Synthetic sweet spots in tight formations by injection of nano encapsulated reactants

Patent metadata

Field	Value
Publication number	US-10358902-B2
Application number	US-201514804717-A
Country	US
Kind code	B2
Filing date	Jul 21, 2015
Priority date	Nov 23, 2011
Publication date	Jul 23, 2019
Grant date	Jul 23, 2019

Abstract

Provided is a method and composition for the in-situ generation of synthetic sweet spots in tight-gas formations. The composition can include gas generating compounds, which upon activation, exothermically react to generate heat and gas. The method of using the composition includes injecting the composition into a tight-gas formation such that upon activation, the heat and gas are generated, resulting in the formation of fractures and microfractures within the formation.

First claim

That which is claimed is:

1. A method for stimulating production of gas in a tight-gas formation, the method comprising the steps of:
injecting into the formation an aqueous solution comprising at least one encapsulated nano particle reactant, said encapsulated nano particle reactant comprising a reactant and a coating, the reactant being capable of reacting with water exothermically to produce a volume of gas, wherein the reactant is selected from the group consisting of sodium dithionite and lithium aluminum hydride;
allowing a delayed erosion of the coating, wherein erosion of the coating releases the reactant;
allowing the reactant to react exothermically to produce a volume of gas;
creating an area of localized pressure within the formation due to the volume of gas; and
producing fractures and microfractures due to the localized pressure, thereby improving production therefrom.

2. The method of claim 1 , further comprising the step of:
allowing the encapsulated nano particle reactant to migrate deep into the formation before reacting.

3. The method of claim 1 , wherein the reactant is selected from the group consisting of reactants that react exothermically with water and components of a redox reaction.

4. The method of claim 1 , wherein the step of allowing a delayed erosion of the coating begins upon a specific trigger mechanism.

5. The method of claim 4 , wherein the specific trigger mechanism is selected from the group consisting of increased temperature, contact with water, contact with acid, contact with hydrocarbon, and combinations thereof.

6. The method of claim 1 , wherein the step of allowing the reactant to react exothermically further produces heat.

7. The method of claim 1 , wherein the step of injecting into the formation an aqueous solution comprising at least one encapsulated reactant is repeated multiple times.

Assignees

• Saudi Arabian Oil Co

Inventors

• Al-Mulhem Abdulrahman Abdulaziz
• Abass Hazim Hussein

Classifications

• E21B43/24

  using heat, e.g. steam injection · CPC title

• C09K8/70 Primary

  characterised by their form or by the form of their components, e.g. foams · CPC title

• C09K2208/10

  Nanoparticle-containing well treatment fluids · CPC title

• C09K8/84

  Compositions based on water or polar solvents (C09K8/66, C09K8/82 take precedence) · CPC title

• C09K2208/32

  Anticorrosion additives · CPC title