Upstream environmental policies require the use of best available and economically sound technology to continually reduce discharge of mud and cuttings waste resulting from drilling operations. Downhole disposal of mud and cuttings waste through hydraulic fracturing provides a zero discharge solution and eliminates future cleanup liabilities when the loop is closed. This downhole disposal technology has shown success in both onshore and offshore drilling operations and is becoming a routine disposal option of complying with environmental legislation concerning discharges of drilling waste. It also offers favorable economics.

Careful job planning, proper operation design, strict quality assurance and systematic monitoring and analysis are the key to the success of waste disposal operations. Important drill cuttings re-injection engineering design and assurance process are presented in this paper. These include job planning, data required for subsurface geology or formation description and logging analysis, criteria for disposal well and injection zone selection and requirement for slurry rheology quality control. Also presented in this paper are design guidelines for injection strategy selection and injection parameters such as injection rate, batch size, shut-in time required for fracture to close on cuttings, injection equipment requirements, and disposal capacity estimates. Issues related to risk management and commingling of drilling waste injection and produced water injection in the same well are also briefly touched.

You can access this article if you purchase or spend a download.