RIASSUNTO
In 1929 the Standard Oil Company of California commenced the development ofa device for obtaining temperatures and pressures in flowing and shut-in wellsand of suitable running equipment for such a recorder. Although simple inprinciple, the recorder has required much experimental work in its development.The various problems have now been solved to such an extent that it is believedthat the apparatus affords a sturdy and reliable means for obtaininginformation regarding depth pressures,-apparatus that may be turned over to awell gang for routine operation.
As an example of the rough usage the device will withstand a recent incidentmay be cited. Owing to failure of the lowering line at the conclusion of a runa recorder was dropped some 6300 ft. through 2~-in. tubing filled with gassyoil. The device was fished out undamaged and with the pressure record intact,although the instrument had been subjected to a,pressure greater than 2300 lb.per sq. in. for some 24 hr. after impact at bottom.
Description of Recorder
The instrument is of the continuous recording loaded spring type (Fig. 1).Temperature is not recorded continuously but is obtained by maximum recordingthermometers in an auxiliary thermometer well. The entire instrument assembly,from bottom of the recorder to top of the socket, is 6~ ft. long and weighsless than 25 lb. The maximum outside diameter of the recorder shell is U:4:in., and all attachments need be no larger. This permits lowering the deviceinside 2-in. tubing.
The operating principle is simple. The well pressure acts upon a piston Aresisted by the extension of spring B. The spring deflection is recorded by astylus C upon paper within the recording drum D.
Springs.-To improve accuracy at lower maximum well pressures fiveinterchangeable spring assemblies are used. These have maximum pressure rangesof from 250 to 5000 lb. per sq. in.