RECOGNITION OF OIL ,GAS AND WATER LAYERS IN THE STRATUM CONTAINING LOW SALINITY FORMATION WATER
Yang Bisong(Logging Company of SPA).NATUR. GAS IND v.20,no.2,pp.42～44;3/25/2000.(ISSN 1000 0976;In Chinese)
The stratum containing low salinity formation water means that formation water salinity is near to mud salinity,their difference being about an order of magnitude.The oil ,gas and water layers in the stratum containing low salinity formation water are difficult to be recognized according to the water saturation values calculated by use of the traditional log interpretation methods,because a certain quantity of natural gas which coagulated in the oil and gas bearing formations(especially in the south part of Zhunge′er Basin,Xinjiang Province)can exert different influences upon the acoustic,density and neutron loggings.When the gas saturation in formation is high,the characters of low neutron,low density,high interval transit time and high resistance are obvious;while the gas saturation is low,these characters of gas bearing formation are not obvious so as to be often ignored.In order to recognize the fluid properties,the generality of three porosity(i.e.neutron,density and acoustic)loggings and resistivity logging (laterolog) in water formations and the anisotropism of them in oil and gas formations should be fully utilized;through an interactive operation by use of the compensated neutron,compensated acoustic,compensated density and resistivity loggings and a magnification of these informations by use of computer technique,it is enough to raise the resolution capabilities of the three porosity and resistivity curves to audio visually indicate the oil ,gas and water layers.The coincidence rate of the log interpretation by these methods is up to 95%.
【CateGory Index】： P618.13