Casing

About: Casing is a research topic. Over the lifetime, 175440 publications have been published within this topic receiving 744760 citations.

A slug test for determining hydraulic conductivity of unconfined aquifers with completely or partially penetrating wells

Abstract: ~. help ed. steady Proc. With the slug test the hydraulic conductivity or transmissibility of an aquifer is determined from the rate of rise of the water level in a well after a certain volume or 'slug' of water is suddenly removed from the welL. The slug test is simpler and quicker than the Theis pumping test because observation wells and pumping the well are not needed. With the slug test the portion of the aquifer 'sampled' for hydraulic conductivity is smaller than that for the pumping test even though with the latter, most of the head loss also occurs within a relatively small distance of the pumped well and the resulting transmissibility primarily reflects the aquifer conditions near the pumped welL. Essentially instantaneous lowering of the water level in a well can be achieved by quickly removing water with a bailer or by partially or completely submerging an object in the water, letting the water level reach equilibrium, and then quickly removing the object. If the aquifer is very permeable, the water level in the well may rise very rapidly. Such rapid rises can be measured with sensitive pressure transducers and fast-response strip chart recorders or x-y plotters. Also it may be possible to isolate portions of the perforated or screened section of the well with special packers for the slug test. This not only reduces the inflow and hence the rate of rise of the water level in the well, but it also makes it possible to determine the vertical distribution of the hydraulic conductivity. Special packer techniques may have to be developed to obtain a good seal, especially for rough casings or perforations. Effective sealing may be achieved with relatively long sections of inflatable stoppers or tubing. The use of long sections of these materials would also reduce leakage flow from the rest of the well to the isolated section between packers. This flow can occur through gravel envelopes or other permeable zones surrounding the casing. Sections of inflatable tubing may have to be long enough to block off the entire part of the well not used for the slug test. High inflation pressures should be used to minimize volume changes in the tubing due to changing water pressures in the isolated section when the head is lowered. So far, solutions for the slug test have been developed only for completely penetrating wells in confined aquifers. Cooper et at. (1967) derived an equation for the rise or fall of the water level in a well after sudden lowering or raising, respectively. Their equation was based on nonsteady flow to a pumped,

Applied drilling engineering

Abstract: This printing includes corrections made since the original publication in 1986. The text presents petroleum engineering science fundamentals as well as example engineering applications involving those fundamentals. Subjects covered include rotary drilling, drilling fluids, cements, drilling hydraulics, rotary-drilling bits, formation pore pressure and fracture resistance, casing design, directional drilling, and deviation control.

Circular stapler for hemorrhoidal surgery

Abstract: A circular sapling instrument for the removal of hemorrhoids has a stapling end effector having a casing, a hollow staple driver within the casing, an annular blade having an open distal end is located within the staple driver, and a elongated interior drive shaft is reciprocable within the staple driver and the annular blade. A first inner chamber is defined between the staple driver and the interior drive shaft, and a second inner chamber is defined between the annular blade and the drive shaft. The first chamber communicates with the second chamber. The casing has an exterior surface and a substantially unobstructed passageway extends within the casing surface, into the first inner chamber, into the second inner chamber, and through the open distal end of the second inner chamber for insertion and withdrawal of a surgical instrument therethrough.

Instrument having rotation device

Abstract: FIELD: medical engineering. SUBSTANCE: device has rotation mechanism, handle and hollow casing. The hollow casing has articulated parts having two and more pairs of end surfaces arranged at an angle to longitudinal casing axis for conjugating to hollow axle. The hollow axle is arranged in perpendicular to the end surfaces. The rotation mechanism has rotating shaft in the inside of the casing and working jaws. The rotating shaft is mounted in proximal casing area with respect to handles. Driven shaft is mounted in deviating part of the instrument. The shafts have gears at their ends being in constant engagement at any rotation angle. The working jaws are engageable with the driven shaft via the screw transmission and hinge system via conic gears. The driven shaft has movable working jaws or one movable jaw. EFFECT: wide range of functional applications; reduced risk of traumatic complications. 5 cl, 12 dwg

Method of manufacturing a cable portion with a fastening member for a vehicle occupant restraint system and cable portion manufactured by using the method

Abstract: This new method connects a cable section (10) to a fastening termination (12) for a vehicle passenger restraint system. The cable section of desired characteristics, is given a plastic casing (14). This is then heated and the fastener is pressed onto the heated part. Preferably the plastic casing is extruded, is heat shrink tubing or is pushed on. It has high dimensional accuracy in respect of its thickness, preferably plus or minus 0.05 mm. It is highly temperature-resistant.