Most oil and gas leases allow the operator to extend possession for an indefinite period by establishing production in paying quantities. We show how this option to “hold by production” (HBP) stimulates the drilling of many wells that would otherwise be uneconomic. Although such wells may superficially appear to be poor investments, in fact they contribute to shareholder value. We also show, ho...

With the introduction of nanotechnology, energy industries envisage a potential revolutionary change in the field of exploration, development and production. Research by universities into such areas as nanosensors, nanomarkers and nanobots to provide valuable data regarding the reservoir are of great focus due to their large potential return on investment, but have yet to yield substantive prod...

We have devised a method, based on a parametric array concept, to create a low-frequency (300-500 kHz) collimated ultrasound beam in fluids highly attenuating to sound. This collimated beam serves as the basis for designing an ultrasound visualization system that can be used in the oil exploration industry for down-hole imaging in drilling fluids. We present the results of two different approac...

The Measurement/Logging While Drilling (M/LWD) system is a kind of sensors system which is used to help oil/gas drilling field technicians to steer well drilling. In M/LWD, several kinds of sensors are installed into drill string to measure the underground logging data during well drilling operations, and a sink within the drill string collects the logging data from the sensors and then transmi...

Currently about 170 impact craters are known on Earth; about one third of those structures are not exposed on the surface and can only be studied by geophysics or drilling. The impact origin of geological structures can only be confirmed by petrographic and geochemical studies; thus, it is of crucial importance to obtain samples of subsurface structures. In addition, structures that have surfac...

The purpose of this study was to compare the performance of chemomechanical caries removal (CMCR) with that of conventional drilling for efficacy of caries removal, time spent, morphological changes and microhardness of surface dentin, and microleakage of subsequent restorations. Forty-six carious deciduous molars were randomly divided into two groups: one each for caries removal by (1) CMCR an...

Piedmont tectonic belts are rich of oil and gas resources, however the intense tectonic stress and broken formation may cause great drilling problems in piedmont structures such as borehole collapse, lost circulation and gas cutting. Through analysis of in situ stress properties, bedding structure and mechanical characteristics, wellbore instability mechanism was expounded from rock mechanics, ...

Public health concerns related to the expansion of unconventional oil and gas drilling have sparked intense debate. In 2012, we published case reports of animals and humans affected by nearby drilling operations. Because of the potential for long-term effects of even low doses of environmental toxicants and the cumulative impact of exposures of multiple chemicals by multiple routes of exposure,...

One of the most significant problems encountered in machining, particularly in drilling, is that of burr formation. Burrs usually comprise of work piece material which has been plastically deformed during the machining process and projects beyond the desired edge of the work piece. The adverse effects of burrs depend on the component application but may include; stress concentration and related...

The accurate control of the wellbore pressure not only prevents lost circulation/blowout and fracturing formation by managing the density of the drilling fluid, but also improves productivity by mitigating reservoir damage. Calculating the geothermal pressure of a geothermal well by constant parameters would easily bring big errors, as the changes of physical, rheological and thermal properties...