The main task of drilling the formation by the bit is done via scraping, crushing and grinding. Discharging the fluid from the bit nozzles is done with high pressure which assists to break the rocks. Different parameters affect the bit selection and design for each drilling formation, but the most important one is drillability that depends on hardness of the formation. In this paper, the design...

Site U1322 is the easternmost site drilled in the Ursa basin by Expedition 308. Of the three sites in the Ursa Basin, Site U1322 has the thinnest sediment cover above the permeable Blue Unit. The principal objectives of drilling Site U1322 were to document rock physical properties at the location of minimal overburden in the Ursa Basin, measure in-situ formation temperature and pressure, docume...

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...

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.

Site U1324 is the westernmost site drilled in the Ursa basin by Expedition 308. Of the three sites in the Ursa Basin, Site U1324 has the thickest sediment loading above the permeable Blue Unit. The principal objectives of drilling Site U1324 were to document rock physical properties at the location of maximal overburden in the Ursa Basin, measure in-situ formation temperature and pressure, docu...

Generally, the drilling mud is divided into three groups of oil (gas oil) and gas based on its base (the main phase), which is often mixed drilling mud from two or more times a mixture of all three fluids that are present at the same time. In this paper, we first investigate the types of drilling flowers, and then we study the pollution of the types of drilling flowers that...

Critical events in industrial drilling should be overcome by engineers while they maintain safety and achieve their targeted operational drilling plans. Geophysical drilling requires maximum awareness of critical situations such as “Kicks”, “Fluid loss” and “Stuck pipe”. These may compromise safety and potentially halt operations with the need of staff rapid evacuations from rigs. In this paper...

The rheological and filtration properties of drilling mud under down-hole conditions may be very different from those measured at ambient pressures and temperatures at the surface. This paper presents the results of an experimental investigation into the temperature and salinity and pH effects on drilling mud rheological and filtration properties. Results are given from tests on water base mud ...

A synthesis of well logs was carried out and drilling mud weight data were analyzed to figure out anomalous high fluid pressure within the Triassic evaporitic cap rock (the Dashtak formation) and study its impact on the geometry of anticlinal traps in the gas rich Gavbandi province located in the southeast part of the Zagros Mountains. The results indicated that the location of anticlinal traps...

It is not possible to directly measure the total mass of gas and liquid in the annulus and geological properties of the reservoir during petroleum exploration and production drilling. Therefore, these parameters and states must be estimated by online estimators with proper measurements. This paper describes a nonlinear Moving Horizon Observer to estimate the annular mass of gas and liquid, and ...