Well Flowmeter for Logging Producing Ability of Gas Sands

Abstract

Abstract The Stanolind flowmeter, which employs a hot-wire anemometer connected in aWheatstone bridge circuit, has proved useful for determining the relativeproductive ability of individual sand members of gas wells. The operation ofthis instrument in measuring gas velocities in the well bore above eachproducing member has provided both a direct and accurate means of analyzingreservoir performance. Results of tests conducted with the well flowmeter in the Hugoton gas field ofwestern Kansas have indicated some rather unusual production characteristics.In two cases it was found that all or the greater part of the total gasproduced was coming from one section in wells where four "pay" sectionshad been perforated individually. These actual measurements contradict in manyinstances the indications of data obtained from electric logs and from coreanalysis; the fact that these latter sources often give incorrect results, demonstrates the necessity of a method, such as is provided by the wellflowmeter, for accurately determining the amount of gas coming from eachproducing member. Introduction In any gas well where a number of pay sections have been perforatedindividually and are producing to a common outlet, the question arises as tothe relative amounts of gas being passed through each set of perforations. Inthe past it has been the policy to depend on core analysis to estimate relativeproductivities, or, where the sections were not cored, to obtain some idea ofproduction characteristics from electric log studies. The weaknesses in thesemethods are readily apparent and indicate the need for more reliable means ofmeasuring gas flow from each zone. The Stanolind flowmeter was developed forthis purpose. Preliminary tests were made with the instrument in the Katy gas field nearHouston; however, the bulk of the routine work with the well flowmeter has beenconfined to the Hugoton gas field in western Kansas, where results obtainedhave been encouraging. A description of the instrument, the field technique employed in testing, and afew of the results obtained in the Hugoton area are discussed in thispaper. Description of Instrument The well flowmeter is 1 ? in. od and 7 ft long; it is entirely self-contained, can be run through tubing as small as 2 in. id in wells with high pressure(4500 psi) and temperature (210'F) and is lowered on a wire line commonly usedfor other instruments of the bottom-hole type at falling rates up to 500'Ft perminute. It will detect gas flow as low as 10'Ft per minute linear velocity, andyet withstand and record velocities of 1000'Ft per minute without damage to thedetecting element. Killing the well is not required nor desirable for running aproduction profile when using the instrument and it is necessary to stop flowfor only a short time. T.P. 2263