Laminated Sand Analysis Available to Purchase

Laminated Sand Analysis is a new computing center technique used to quantitatively evaluate the shaliness, porosity, and water saturation of beds as thin as 4 cm. A high-resolution sensor for dielectric measurements is used to define the thickness and shaliness of the individual beds. This shale indicator is not affected by changes in porosity and water saturation and has a vertical resolution of 4 cm. Determining the resistivities of thin beds is difficult because of the poor vertical resolution (about8 ft) of deep induction logs. This new shale indicator is used to greatly enhance the vertical resolution of the deep induction log by redistributing the measured resistivity among the thin beds. The only analyst input needed is the resistivity of the bound water. A geometric factor model of induction sonde response is used in combination with the dual water model of shaly sand resistivity to compute this high-resolution resistivity curve. The results of this technique have been tested using the program reported by Anderson and Gianzero. This program computes a synthetic induction resistivity curve from the input resistivities of a series of beds. Results indicate that the technique of determining thin-bed resistivity described in this paper is valid within the range of two-tenths to 10 Q-m. Once shaliness and resistivity have been determined, these values are input to a log analysis program for high-resolution computations of porosity, water saturation, permeability, and reserves. These outputs allow decisions about laminated zones to be made based upon engineering and economics, rather than on hunches and rules of thumb. Log examples from onshore Louisiana and offshore Texas are presented to demonstrate the technique.