Settable, form-filling loss circulation control compositions comprising in situ foamed non-hydraulic sorel cement systems and method of use

Patent metadata

Field	Value
Publication number	US-10385255-B2
Application number	US-201816137919-A
Country	US
Kind code	B2
Filing date	Sep 21, 2018
Priority date	Jan 24, 2018
Publication date	Aug 20, 2019
Grant date	Aug 20, 2019

Abstract

This document relates to settable, non-hydraulic foamed cement compositions comprising nitrogen gas-generating compositions used for loss circulation control.

First claim

What is claimed is:

1. A foamed cementitious composition, comprising:
magnesium oxide (MgO);
a salt selected from the group consisting of magnesium chloride (MgCl 2 ), magnesium sulfate (MgSO 4 ), ammonium hydrogen phosphate (NH 4 H 2 PO 4 ), and hydrates thereof;
a nitrogen gas-generating compound;
a foam surfactant; and
an oxidizer.

2. The composition of claim 1 , wherein the salt is magnesium chloride hexahydrate (MgCl 2 .6H 2 O).

3. The composition of claim 1 , wherein the foam surfactant is selected from the group consisting of an alkyl sulfate salt with a C 12 -C 14 carbon chain, a betaine, and a hydroxysultaine.

4. The composition of claim 3 , wherein the foam surfactant is cocoamidopropyl hydroxysultaine.

5. The composition of claim 1 , wherein the nitrogen gas-generating compound is an azo compound.

6. The composition of claim 5 , wherein the azo compound is azodicarbonamide.

7. The composition of claim 5 , wherein the azo compound is about 1% to about 10% by weight of the MgO.

8. The composition of claim 5 , further comprising an amine activator selected from the group consisting of carbohydrazide (CHZ), tetraethylenepentamine (TEPA), and hydrazine sulfate.

9. The composition of claim 8 , wherein the weight ratio of the azo compound to the amine activator is about 5:1 to about 1:5.

10. The composition of claim 8 , wherein the amine activator is CHZ.

11. The composition of claim 1 , further comprising a set retarder selected from the group consisting of hexametaphosphate, sodium borate, sodium citrate, citric acid, and an aminophosphonate.

12. The composition of claim 1 , further comprising a viscosifier.

13. The composition of claim 1 , wherein the pH of the foamed cementitious composition is greater than about 4.

Assignees

• Saudi Arabian Oil Co

Inventors

• Reddy B Raghava

Classifications

• C04B2111/00689

  of the setting type · CPC title

• C09K8/487 Primary

  Fluid loss control additives; Additives for reducing or preventing circulation loss · CPC title

• C04B28/34

  containing cold phosphate binders · CPC title

• C04B28/32

  Magnesium oxychloride cements, e.g. Sorel cement · CPC title

• C04B9/02

  Magnesium cements containing chlorides, e.g. Sorel cement · CPC title