Drilling fluid is critical for the safely operation of drilling activities, the protection of reservoir and the success of oil and gas investment.
Because the importance of drilling fluid, a good amount of research and development work have been conducted to enhance the performance of drilling fluid. Many kinds of additives are added to drilling fluid to turn the property of drilling fluid to meet the needs of certain drilling jobs. Oil based drilling mud is one of the major kind of drilling fluid widely used in the oil and gas industry. Due to the cost of the oil based mud, and the potential thread if oil based mud is dumped, many countries put forward regulations for the recovery of the fluid in oil based mud. It is necessary to recover the fluid in the oil-based drilling fluid to save drilling cost, and to protect environment.
In oil and gas drilling process major portion of the fluid from oil based mud (OBM) is recycled into the drilling fluid system through shale shakers, decanter centrifuges. Yet there is still a big percentage of fluid from OBM being attached to the surface of drilling cuts. Typically, the OOC (oil on cutting) can be up to 15-20%. In other words, about 1/5 of the expensive drilling fluid in OBM is wasted.
A typical application of drilling cut dryer is to position the system in a center location, where transportation vehicles send drilling cut to the location and unload the drilling cut into a collect bin. A conveyor will transport the drilling cut to a hopper, which is mounted on top of the cutting dryer. The cutting comes into the cutting dryer, and the centrifugal force generated by the rotation of rotating basket can be a few hundreds time of G force and thus force the fluid, along with smaller particles, to go through the screen basket and is collected through channel system and flow to a collector, while the solids accumulated on the screen basket is pushed down by tungsten carbide enforced cutting knife and discharged at the bottom of cutting dryer.
Collected fluid has certain concentration of solids under 0.25mm, which needs to be removed by next equipment, decanter centrifuge. GN Solids Control manufactures a series of decanter centrifuge up to 30 inch bowl.
After being processed by decanter centrifuge, the solids in the collected fluids is minimized and is ready to be used for drilling operation again.
A major advantage of vertical cutting dryer is its ability to generate profit, in addition to environment protection, because the fluid is expensive. The base fluid is diesel, which is already costly. The addition of different chemicals, to improve flow dynamic, to increase holding capability of drilling fluid, to protect reservoir formations, to help to dissipate heat generated by the drilling process, and to improve lubrication capability of drill bit, tremendously increased the cost of oil based drilling fluid.
One of GN vertical drilling cut dryer was used by Great Wall Drill. According to the operation manager of the drilling rig, they can save up to USD 3,000 for each cubic meter of fluid recovered. Usually the processing capability of such equipment can process 10 m3/h of drilling cut, and recover 1m3 of drilling fluid. In another word, a vertical drilling cut dryer can recover 8 m3 of drilling fluid an hour, which can save the drilling rig at least $15,000 per each 8 hour shift.
If we put it the other way, the cost of a GN vertical cutting dryer can be recovered in a few months and for the rest of the time, profit generated would be unbelievable.