Pitless means no need to dig a pit on the ground to collect the drilling cuttings. Nowadays, though the solids control system is widely used in oil drilling, some drillers still dig a mud pit on the ground to collect the drilling waste cuttings discharged out from the primary solids control equipment.
So long as the drilling rig is working, the solids control system has to be working all the time as the used drilling fluids is continuously coming out from the drilling well. With the issue of much strict environment protection regulation, the driller need find a solution to reduce the volume of the discharged drilling cuttings; in the meanwhile, much more drilling fluids could be recovered to reduce the drilling cost. And then they got a
conclusion, if I can establish a pitless drilling cutting disposal system, all the problems would be solved.
Pitless drilling cuttings disposal system requires a good connection between the traditional solids control system and waste cuttings management system. The most important is there should be a final solution on how to make the discharges environmental friendly. For the waste cuttings out of the shale shaker and cyclone unit, no matter water base or oil base. We have the high G force drying shaker and vertical cutting dryer unit to make the cutting much dryer so that more drilling fluids could be recovered. The recovered drilling fluids would be pumped
to a high speed centrifuge for separation of fine solids in the drilling fluids. After treated by the centrifuge, the drilling fluids would flow back into the storage tank for drilling reuse. The screw conveyor is used to transfer the drilling cuttings from shaker unit to the cuttings dryer machine. Therefore, it is no need to dig a mud pit, or at least, a large and deep mud pit on the ground to collect the drilling cuttings. We nearly realize
the pitless before the final disposal of the dry cuttings.
There are Thermal Desorption Unit and solidification unit could be used to dispose the cuttings from the high G force drying shaker and Verti G dryer. These 2 systems could make the cuttings none hazardous for environment. Finally, the pitless drilling cuttings disposal system is established.