Oil and gas drilling operations use drilling fluids (mud) to lubricate the drill bit and stem, transport formation cuttings to the surface, and seal off porous geologic formations. Following completion of the well, waste drilling fluid is often applied to cropland. We studied potential changes in soil compaction as indicated by cone penetration resistance, pH, electrical conductivity (EC(e)), s...

It is now commonplace for non-destructive X-ray computed tomography (CT) scans to be taken of core recovered during a drilling project. However, other forms of tomographic scanning are available, and these may be particularly useful for core that does not possess significant contrasts in density and/or atomic number to which X-rays are sensitive. Here, we compare CT and neutron tomography (NT) ...

today’s energy reauiraments have produced an increase in drilling activities all around the world. among this situation is the fact that all the operators are trying to minimize cost without reduction in quality. so, they are looking for new types of contracts between all drilling companies, contractors and suppliers until that with make agreement between them have successful operations. in thi...

Solids control equipment at the rig site is used to remove rock cuttings or low-gravity solids (LGS) from drilling fluids to allow the fluid to return to the active system in a re-usable condition. Typical equipment, such as shakers and centrifuges, remove LGS particles greater than 5-7 microns. Build up of finer solids in the fluid can create problems for efficient drilling such as drillpipe s...

OBJECTIVE To assess if the screw design (self-drilling/self-tapping) and the pilot hole tapping could affect the insertion torque and screw pullout strength of the screw used in anterior fixation of the cervical spine. METHODS Forty self-tapping screws and 20 self-drilling screws were inserted into 10 models of artificial bone and 10 cervical vertebrae of sheep. The studied parameters were th...

It is easy to live for the day. All lazybones do that and legitimately those who have finally taken a rest and enjoy in a relaxed way what is offered to them. The more eventful the better since then it is easy to forget what happened before and since unconnected impressions can be grasped in a particularly fresh way, in a virtually raw way. And in the same way as one might live for the moment, ...

As the name indicates, a renewal process is one that “renews” itself regularly. That is, there is a sequence of times {Tn, n ∈ Z} such that the process after time Tn is independent of what happened before that time and has a distribution that does not depend on n. We have seen examples of such processes before. As a simple example, one could consider a Poisson process with jump times Tn. As ano...

Rotary drilling belongs to the key methods of rock separation not only in mining, but also in wider areas of geotechnologies 1, 2 . The most efficient separation of rocks is in so-called volume area which can be achieved with the correct choice of work tool and work mode while taking into account the geomechanical properties of rock separation. Theoretical research of rock separation by rotary ...

The oil well drilling process is the selected representative of a challenging industrial process. The drilling process is becoming more complex as oil fields mature and technology evolves. At the same time, the amount of information is increasing in volume and frequency. Although technology is advancing, failures occur at almost the same rate as before, leading to loss of valuable time. Wheneve...

Drilling of the skull base bone without damaging the important inside structures and with the correct orientation is very difficult even with the help of the anatomical landmarks. Monitoring of the location and direction of the drill tip and indications of the removed part of the bone during the drilling procedure enhances safety and achieves less invasive neurosurgery. We have developed a nove...