Aqueous solution and method for use thereof

Patent metadata

Field	Value
Publication number	US-9476287-B2
Application number	US-201314072395-A
Country	US
Kind code	B2
Filing date	Nov 5, 2013
Priority date	Nov 5, 2013
Publication date	Oct 25, 2016
Grant date	Oct 25, 2016

Abstract

Oilfield treatment compositions contain water, hydrochloric acid at a concentration between 15 wt % and 45.7 wt % and a first and second fixing agent. The first fixing agent comprises urea, a urea derivative or both. The second fixing agent may be a mixture or amines and alcohols. These compositions provide corrosion inhibition when exposed to steel. The compositions may also contain an inhibitor aid.

First claim

We claim:

1. A method for treating a subterranean well having a wellbore, at least one steel casing and a formation, comprising:
(i) preparing a composition comprising water at a concentration lower than or equal to 20 wt %, hydrochloric acid at a treatment concentration between 15 wt % and 45.7 wt %, a first fixing agent comprising urea, a urea derivative or both, and a second fixing agent, wherein the first fixing agent:hydrochloric acid molar ratio is between 0.4 and 3.0 inclusive;
(ii) providing an oilfield treatment fluid including the composition to a high pressure pump, wherein the oilfield treatment fluid is not in the form of an emulsion and does not include a separate oil phase; and
(iii) operating the high pressure pump to place the composition in the well such that the composition contacts the at least one steel casing.

2. The method of claim 1 , wherein the second fixing agent comprises a mixture of amines and alcohols, and the concentration of the second fixing agent is between 0.1 wt % and 0.5 wt % inclusive.

3. The method of claim 1 , wherein the composition further comprises an inhibitor aid comprising a mixture of phenyl ketones and quaternary amines, wherein the concentration of the inhibitor aid is between 0.4 wt % and 0.8 wt % inclusive.

4. The method of claim 1 , wherein the composition further comprises hydrofluoric acid at a concentration higher than or equal to 0.25 wt %.

5. The method of claim 1 , wherein the hydrochloric acid, prior to inclusion in the composition, is transported in an aqueous solution to a wellsite, the hydrochloric acid having a concentration between 28 wt % and 45.7 wt %, and the treating further comprises providing the transported hydrochloric acid at the treatment concentration before providing the oilfield treatment fluid to the high pressure pump.

6. The method of claim 1 , wherein operating the pump comprises at least one of:
(i) injecting the treatment fluid into the formation at matrix rates;
(ii) injecting the treatment fluid into the formation at a pressure equal to or greater than that necessary to fracture the formation; and
(iii) contacting at least one of the wellbore and the formation with the oilfield treatment fluid.

Assignees

• Schlumberger Technology Corp

Inventors

• Jiang Li
• Lecerf Bruno
• Jones Timothy G J
• Ziauddin Murtaza
• Hutchins Richard
• He Jian
• Li Jack
• Kraemer Chad

Classifications

• C09K8/54 Primary

  Compositions for in situ inhibition of corrosion in boreholes or wells · CPC title

• C09K2208/32

  Anticorrosion additives · CPC title

• C23F11/04

  in markedly acid liquids · CPC title

• E21B43/28

  Dissolving minerals other than hydrocarbons, e.g. by an alkaline or acid leaching agent (E21B43/241 takes precedence) · CPC title

• E21B41/02 Primary

  in situ inhibition of corrosion in boreholes or wells · CPC title