Gas Cut Research Articles

Business Strategy Four‐Year Automation Program Helps Lone Star Gas Cut Costs

Business Strategy Four‐Year Automation Program Helps Lone Star Gas Cut Costs

Parametric acoustic flow meter

First Page

The Source of Increased Carbon Content in Gas Cut Steel Surfaces

It is an established fact that carbon migration at the surface of a cut does occur, although as yet there appears to be no complete agreement between investigators as to exactly how this enrichment near the cut surface is brought about.

Bottom-Hole Pressure Reduction Due to Gas Cut Mud

Abstract Strong's equation for calculating bottom-hole pressure reduction due to gas cutting of drilling mud is corrected, resulting in a simpler equation which is easier to use. Use of the equation is illustrated by examples. It is shown that reduction of weight of a 10 lb/gal mud by 50 per cent at the surface due to gas cutting produces only a 3 per cent decrease in hydrostatic head at the bottom of a 5,000-ft well. It is also shown that at the surface 5 volumes of air per volume of mud are required to reduce the apparent mud weight from 8.5 to 6.5 lb/gal in a 3,000-ft well. Illustrative graphs are included to show the effect of various degrees of gas cutting on apparent mud weight at depths of 2,000, 5,000 and 10,000 ft and to show variation of apparent mud weight, with depth for a 100 lb/cu ft (13.37 lb/gal) mud gas cut to 90 lb/cu ft (12.03 lb/gal) at the surface. Introduction In 1938, Strong published the following equation for calculating reduction in bottom-hole pressure due to gas cutting of drilling mud. This equation was recently found to contain an error due to an incorrect expression for variation of volume fraction of gas with pressure. Values calculated by the original equation are close to the correct values for small percentages of gas for which it was derived but become increasingly erroneous as the gas content increases and are completely unusable at the very high gas contents employed in aerated mud.

高張力鋼の熔接性に及ぼすニツケルおよびクロムの影響(第3報)

An extensive investigation was performed of the effects of nickel and chromium contents on weldability of high tensile manganese-silicon steels, forteen experimental and four commertial, which contained nickel or chromium less than 1%. The present paper, the third part, describes the results of the following tests, namely, slit-type cracking, CTS cracking, Gas cut bend, and Fillet-weld break tests. From the results of those tests, the following conclusions have been obtained;1. The degrees of cracking in the slit-type cracking test were not affected with increase of nickel up to about 0.9%, while increased greatly when chromium exceeded about 0.5% of content.2. In the CTS test specimens, distinct underbead cracks were observed frequently on steels which contained over 0.49% of chromium. However, the degrees of cracking in CTS test were not always related to that of slit-type cracking test, since many micro-cracks due to banded inclusions occured in the direction of rolling especially in the CTS test specimens. Generally, CTS cracking test appeared to be less sensitive than slit-type cracking test.3. Bending ductility of the gas cut bend test specimens was not almost affected by variation in nickel or chromium content.4. The degrees of pull out fracture in fillet-weld bereak test increased more with increase of nickel content than that of chromium.