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...

Deep-water drilling in the Gulf of Mexico could resume within weeks under a policy by the US government, which has come under increasing criticism from the oil industry and politicians in the region over the impact of the drilling halt and worries from scientists that the full impact has not yet been assessed. Oil and gas exploration in the gulf’s deep waters has been stopped since May, when Ob...

Unconventional gas includes tight sandstone gas, shale coalbed methane, and natural hydrate. With huge reserves, unconventional has become the most important resource successor after end of “Easy Oil era.” The drilling fluid is an indispensable wellbore working for with multiple functions. polymer (PDF) common, longest developed, diverse type. advantages easily controlled rheology, convenient o...

For porous medium containing multiphase fluid, such as oil-wetted with oil–water dual phase its fluid interface will also produce electric double layer (EDL), which play a role in the seismoelectric effects. At this time, principle of effects is more complex. The existing theory for Pride used water-saturated formation, cannot meet actual needs theoretical research exploration formation fluid. ...

Abstract. Good project planning provides the basis for successful offshore well drilling projects. In this domain planning occurs in two phases: an onshore phase develops a project plan; and an offshore phase implements the plan and tracks actual progress compared to the initial plan that was created onshore. The reuse of project plans is already prevalent within the oil and gas industry. A Per...

Perforation in internal upset transition zone is one of the main failure styles for drill pipes. Due to the flow channel specificity of upset transition zone, in this paper, drill pipe failure analysis from the point of flow erosion was put forward. Flow field of drilling fluid in the internal upset transition zone of U127 mm API IEU S135 drill pipe under various conditions were obtained using ...

the most costly operation in the oil exploration is the well network drilling. one of the most effectiveways to reduce the cost of drilling networks is decreasing the number of the required wells byselecting the optimum situation of the rig placement. in this paper, balas algorithm is used as a modelfor optimizing the cost function in oil well network, where the vertical and directional drillin...

Oil and gas offshore exploration drilling and production facilities in cold climate and Arctic environmental conditions need various design considerations and operational preparation for intended operations. Offshore winterization of drilling systems and equipment is considered to be one of the essential aspects for ensuring that a facility is capable of and suitably prepared for operations in ...