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 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...

Drilling fluid, as an essential part of the drilling process, directly affects efficiency and safety drilling. The expansion-type oil-based leak-proof plugging fluid system is a new type with advantages such plugging, good permeability, high bearing capacity, has become hot topic in research. This paper will provide detailed introduction to composition, performance, application system.

In oil and gas and geothermal installations, open channels followed by sieves for removal of drill cuttings, are used to monitor the quality and quantity of the drilling fluids. Drilling fluid flow rate is difficult to measure due to the varying flow conditions (e.g., wavy, turbulent and irregular) and the presence of drilling cuttings and gas bubbles. Inclusion of a Venturi section in the open...

Summary In the placement process of cement slurry, treatment fluids such as spacer are pumped ahead cementitious slurry to minimize contamination by drilling fluid and ensure superior bonding casing formation. The discussed in this work can harden with time act a settable spacer. This characteristic be an advantage for well integrity if some pockets left annulus. Rheological compatibility diffe...

Multiplicity of the effective factors in drilling reflects the complexity of the interaction between rock mass and drilling bit, which is followed by the dependence of parameters and non-linear relationships between them. Rock mass or, in other words, the formation intended for drilling, as the drilling environment, plays a very essential role in the drilling speed, depreciation of drilling bit...

fluid invasion from water-based drilling mud (wbdm) into the shale formations causes swelling,high pressure zone near the wellbore wall, and eventually wellbore instability problems duringdrilling operations. for the stability of the wellbore, physical plugging of nanoscale pore throats couldbe considered as a logical approach toward avoiding the fluid invasion into the shale formation. thispap...

Deep-subsurface samples obtained by deep drilling are likely to be contaminated with mesophilic microorganisms in the drilling fluid, and this could affect determination of the community structure of the geothermal microflora using 16S rRNA gene clone library analysis. To eliminate possible contamination by PCR-amplified 16S rRNA genes from mesophiles, a combined thermal denaturation and enzyme...