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-10544351-B2
Application number	US-201916454925-A
Country	US
Kind code	B2
Filing date	Jun 27, 2019
Priority date	Jan 24, 2018
Publication date	Jan 28, 2020
Grant date	Jan 28, 2020

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 method of treating a lost circulation zone, the method comprising:
a) forming a foamed cementitious composition comprising:
magnesium oxide (MgO);
a salt comprising at least one of magnesium chloride (MgCl 2 ), magnesium sulfate (MgSO 4 ), ammonium hydrogen phosphate (NH 4 H 2 PO 4 ), or a hydrate thereof;
a nitrogen gas-generating compound; and
a foam surfactant; and

b) introducing the foamed cementitious composition into the lost circulation zone.

2. The method of claim 1 , wherein the nitrogen gas-generating compound comprises an azo compound.

3. The method of claim 2 , wherein the azo compound is about 1% to about 10% by weight of the MgO.

4. The method of claim 2 , comprising an amine activator comprising at least one of carbohydrazide (CHZ), tetraethylenepentamine (TEPA), or hydrazine sulfate.

5. The method of claim 4 , wherein the weight ratio of the azo compound to the amine activator is about 5:1 to about 1:5.

6. A method of treating a lost circulation zone fluidly connected to a wellbore, the method comprising:
a) forming a foamed cementitious composition comprising:
magnesium oxide (MgO);
a salt comprising at least one of magnesium chloride (MgCl 2 ), magnesium sulfate (MgSO 4 ), ammonium hydrogen phosphate (NH 4 H 2 PO 4 ), or a hydrate thereof;
a hydrazide or a semi-carbazide, or both;
an oxidizer; and
a foam surfactant; and

b) introducing the foamed cementitious composition into the lost circulation zone.

7. The method of claim 6 , wherein the oxidizer comprises at least one of peroxide, persulfate, percarbonate, perbromate, perborate salts of ammonium, alkali earth metals, or alkaline earth metals.

8. The method of claim 7 , wherein the weight ratio of the hydrazide or semi-carbazide to the oxidizer is about 1:0.25 to about 1:5.

Assignees

• Saudi Arabian Oil Co

Inventors

• Reddy B Raghava

Classifications

• C04B2111/00689

  of the setting type · CPC title

• C04B9/04

  Magnesium cements containing sulfates, nitrates, phosphates or fluorides · CPC title

• C04B28/34

  containing cold phosphate binders · CPC title

• C09K8/487 Primary

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

• C04B28/32

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