公开(公告)号：US11414589B2

公开(公告)日：2022-08-16

申请号：US16749418

申请日：2020-01-22

Applicant: KING FAHD UNIVERSITY OF PETROLEUM AND MINERALS

Inventor： Salaheldin Elkatatny ,  Abdelmjeed Mohamed ,  Salem Basfer

IPC: E21B37/00 ,  C09K8/528 ,  E21B21/00

Abstract: A method of removing calcium carbonate-containing oil-based filter cake from a wellbore involving contacting the calcium carbonate-containing oil-based filter cake with a biodegradable acid solution of water, hydrochloric acid, formic acid, citric acid, a surfactant, and a glycol ether mutual solvent. The method is performed at a pressure of 200 to 400 psi and a temperature of 50 to 125° C. The method removes calcium carbonate-containing oil-based filter cake made of a water-in-oil emulsion, calcium carbonate, a primary emulsifier, a secondary emulsifier, a contamination treatment agent, a viscosity control agent, a filtration control agent. The method meets industry standard steel corrosion rates of less than 0.049 lb/ft2 per day. Also disclosed is a biodegradable acid solution of water, hydrochloric acid, formic acid, citric acid, a surfactant, and a glycol ether mutual solvent that meets OECD 301B thresholds for ready biodegradability.

公开(公告)号：US20210222050A1

公开(公告)日：2021-07-22

申请号：US16749418

申请日：2020-01-22

Applicant: KING FAHD UNIVERSITY OF PETROLEUM AND MINERALS

Inventor： Salaheldin Elkatatny ,  Abdelmjeed Mohamed ,  Salem Basfer

IPC: C09K8/528 ,  E21B37/00

Abstract: A method of removing calcium carbonate-containing oil-based filter cake from a wellbore involving contacting the calcium carbonate-containing oil-based filter cake with a biodegradable acid solution of water, hydrochloric acid, formic acid, citric acid, a surfactant, and a glycol ether mutual solvent. The method is performed at a pressure of 200 to 400 psi and a temperature of 50 to 125° C. The method removes calcium carbonate-containing oil-based filter cake made of a water-in-oil emulsion, calcium carbonate, a primary emulsifier, a secondary emulsifier, a contamination treatment agent, a viscosity control agent, a filtration control agent. The method meets industry standard steel corrosion rates of less than 0.049 lb/ft2 per day. Also disclosed is a biodegradable acid solution of water, hydrochloric acid, formic acid, citric acid, a surfactant, and a glycol ether mutual solvent that meets OECD 301B thresholds for ready biodegradability.