Shale shaker

Earlier on when we described the cutting action of the drill bit we learned about the drilling fluid or mud. The mud cools the bit and also removes the cuttings by carrying them up the hole outside the drill pipe. At the surface the mud runs over a number of moving screens, the shale shakers (Fig. 3.11) which remove the cutting for disposal. The fine particles which pass through the screens are then removed by desanders and desilters, usually hydrocyclones. 

The normally good lubricating qualities of mud can be lost if cuttings, particularly fine sand, are not effectively separated from the mud. Adequate settling pits and shale shakers usually eliminate this trouble. Desanders are used occasionally. 

Uintaite is not easily water wet with most surfactants. Thus, stable dispersions of uintaite are often difficult to achieve, particularly in the presence of salts, calcium, solids and other drilling fluid contaminants and/or in the presence of diesel oil. The uintaite must be readily dispersible and must remain water wet otherwise it will coalesce and be separated from the drilling fluid, along with cuttings at the shale shaker or in the circulating pits. Surfactants and emulsifiers are often used with uintaite drilling mud additives. 

Donovan, T.J., Roberts, A.A. and Dalziel, M.C., 1981. Epigenetic zoning in surface and near-surface rocks resulting from seepage-induced redox gradients, Velma oil field, Oklahoma a synopsis. Oklahoma City Geological Society Shale Shaker, 32(3) 1-7. 

Ferguson, T.D., 1979a The subsurface alteration and mineralisation of Permina red beds overlying several oil fields in southern Oklahoma Part I. Oklahoma City Geologieal Society Shale Shaker, 29 172-178. 

Lilbum, R.A. and Alshaieb, Z., 1984. Geochemistry and isotopic composition of hydrocarbon-induced diagenetic aureole (HIDA), Cement, Oklahoma. Oklahoma City Geological Society Shale Shaker, 34 57-67. 

The rheological properties of the drilling fluid have a marked influence on the performance of solids control equipment. Froment et al. (163) have pointed out that an increase in the viscosity of the drilling fluid will decrease the flow rate capacity of the shale shaker and will increase the minimum particle size of the solids in the separated stream from a hydrocyclone that is returned to the circulating drilling fluid. For example, Figure 59 shows the particle size distribution of the solids in the under flow from a hydrocyclone. The density and viscosity of the drilling fluid are observed to have a marked effect on the separation characteristics of the hydrocyclone. 

The returning mud can contain natural gases or other flammable materials which will collect in and aroimd the shale shaker/conveyor area or in other work areas. Because of the risk of a fire or an explosion if they ignite, special monitoring sensors and explosion-proof certified equipment is commonly installed, and workers are advised to take safety precautions. The mud is then pumped back down the hole and further re-circulated. After testing, the mud is... 

ASME Shale Shaker Committee (2005). The Drilling Fluids Processing Handbook. ISBN 0-7506-7775-9. 

Shale shaker separates drill cuttings from the drilling fluid before it is pumped back down the wellbore. 

Flow line is a large-diameter pipe that is attached to the bell nipple and extends to the shale shakers to facilitate the flow of drilling fluid back to the mud tanks. 

Circulation system—pipes, valves, pumps, mud-return line, shale shaker, shale slide, mud mixing hopper, mud pits, reserve pit... 

In any plant there are certain obvious hazards, for example, fire hazard in shale shaker area of offshore facility or generator are hydrogen cooled generators in power plants. HAZID is not meant to identify such kinds of hazards only. There needs to be some realty and lateral thinking power while carrying out the study. Also there always exist certain chances of a hazard in a complex event, on account of a series of activities. In the study this can be revealed. These characteristics shall include but are not limited to the following ... 

Site preparation work often requires heavy equipment, such as bulldozers and scrapers, to level the drill pad and surrounding area. Anytime employees are working under this type of equipment (for example doing repair work), the blades must be blocked or fully lowered. This is also the case when working inside equipment that has an overhead door that could close on an employee, like a shale shaker or water tank. 

Once production has started on the site the four-foot height threshold remains in place. Drill rigs have many elevated surfaces and if they are four-feet or more above a lower level there must be some type of fall protection in use. A typical type of fall protection will be the standard guardrail. Places where guardrails will often be installed include the rig floor, the platform holding the shale shakers, the platform above the mud tanks, and the platform above the drilling fluid equipment. 

Exposures to H2S at concentrations as low as 600 ppm can cause death in a matter of minutes due to paralysis of the respiratory system. The gas is colorless and flammable. It is also 19% more dense than air. Therefore any H2S that leaks is likely to accumulate at a low point such as pits, trenches, enclosed well bays and cellars, sumps, the tops of floating roof tanks, buildings, shale shakers and portable containers. H2S is soluble in many liquids, including hydrocarbons. However, H2S mixed with natural gas may form a lighter-than-air mixture. In general, the fact that H2S is heavier than air is a statement that should be used with care, particularly when concentrations of the gas are low (say less than 100 ppm). 

Circular saw) (Oil vapour and mist from drilling mud in shale-shaker) (Car traffic)... 

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