S.M.A.R.T.S. Stimulation Monitoring and Reservoir Testing Software™ Waste Disposal Mode
Waste disposal involves taking different classes of material and injecting that liquefied slurry into a non producing zone of a deep earth formation, in such a manner that it will never breach to the surface or affect aquifers of the area or other production zones.
Waste disposal materials come in a number of different forms. Some of the more common petroleum operations generated related wastes are as follows.
Production water from the formation being produced.
Stimulation injection fluids that are flowed back from the well after treatment.
Waste material generated during the drilling process such as muds, gels, drilling fines, and used or product petroleum products such as diesel.
In some operations the drilling waste has been pit disposed. Sometimes this disposal method must be removed. The material including rocks and plant material, must then be processed using a mining method concerning a ball mill and the material crushed to the consistency of talc and then injected into the waste disposal well.
Disposal design methods also vary. The following is a brief description of some of the waste disposal methods and the use of Smarts32 as the computerized treatment monitoring center.
During injection, down hole pressure is watched to prevent it from exceeding that of the bottom hole break down pressure via Smarts32 alert methods. Injection is monitored with Smarts32 to insure this and that the entire injection process is in matrix flow. These jobs are pumped as batches of material as delivered and the injection times are short and the well remaining static until the next batch is received.
During drilling, waste liquids are stored in tanks until filled. Drilling is then stopped and via a pumping skid, a manned Smarts32 computer is used to monitor and insure that the down hole injection pressures remains below the break down pressure. The waste is injected down the annulus of the well being drilled, into a perforated non-producing zone a distance above the targeted production zone. When the drilling rig is removed, all drilling generated waste has been disposed.
Some waste disposal processes do not work with batch jobs (multiple injections and shut downs per 24 hour period). They use continuous injection methods at above breakdown pressures and intentionally create fractures within the treatment zone for waste storage. The injection times are continuous and may last for a number of days in a row, or even weeks, for 24 hours a day, seven days a week.
The Smarts32 waste disposal mode has been uniquely written for monitoring of the above methods and is used by several major Oil and Gas companies for their waste disposal operations. Smarts32 also has an extended run mode for continuous monitoring for multiple day or months injections. A single screen shot of an actual waste disposal well operation is presented below. This represents only one of the many screens as well as custom plots and text screens available to the Smarts32 user. In this case a batch disposal job was being pumped disposing of an oil based gel using the matrix flow only method.
Below is an example of waste disposal of a water based mud. The well had been treating high and the BHP analysis indicated it was no longer in matrix flow but creating a fracture since the BHP was above the alert line for the fracturing pressure (upper left window) and above closure pressure (upper right window). The waste disposal process was temporarily shut down until the well could be cleaned up using matrix acidizing which lowered the near well bore skin.