NID-2-based Dipmeter Technique
Scientific-Production Enterprise of Geophysical Technique,
42, Mira st., Pyatigorsk, Russia
The NID-2-based Dipmeter Technique is designed to determine dips, structure and texture features of geological bodies from thear electrical, mechanical (stress-strain) and magnetic properties. The technology includes the NID-2 dipmeter testing, diplog measurements in boreholes, processing and interpretation of the data on PC in automatic and interactive modes using Linid-2 software under MS Windows95 Ô . Dip data are determined discretely for each overlying and underlying geological body surface (of a stratum, thin bed, fraqture, etc) from changes of their electrical resistivity and degree of sterss-strain destruction. Six microresistivity sensors permit to determine average dip values for each geological body boundary to recognize unflat and broken boundaries, start to study structure and texture indications of a geological body. Application of modern technique such as multielement microlaterolog tool, z-accelerometer, three-ferrosonde magnetometer, unclearenced spring radius sensors, liquid zenith angle sensor and other progressive means and computer processing methods allowed to considerably increase accuracy and expend the spheare of use of the new tool and technology. The NID-2 tool specification and coloured photo of the dipmeter is given.
Graphical presentation of the initial and intermediate data and of the processing results is provided as coloured frames on display in the depth scale, suited for observing and interactive mode processing. Linid-2 software display includes depth column, working area (six microconductivity or caliper curves), vertical well sections, inclinometer nomograph with a synthetic microlaterlog conductivity curve and a z-magnetometer curve, dip data column, borehole wall image column and 3-D oriented core image column. A hard copy of the diplog is available as a coloured plot in the depth scales divisible by 10.
High vertical resolution advantages of dip determination using the NID-2 Technique to evaluate structure and texture features of geological bodies to survey oil deposits in the Western Siberia region are demonstrated in comparison with the 4-Arm 1016EA Western Atlas Dipmeter tool measurements. The data obtained change our point of view to the problem of structure dip statistical determination. A large number of dips showing cross bedding (herringbone, scalloped, dotted, etc) requires improvements in the known principles and methods of structure dip determination from dip vertical statistics phenomemon.