METHOD ESTABLISHING GEOLOGICAL PROPERTIES OF TERRIGENOUS ROCK IN SPACE NEAR HOLE BY DATA OF GEOPHYSICAL EXAMINATIONS OF SECTIONS OF HOLES

• Main Authors: AFANAS'EV S.V, AFANAS'EV A.V, AFANAS'EV V.S
• Format: Patent
• Language: English; Russian
• Published: 20.12.2003
• Edition: 7
• Subjects: EARTH DRILLING; EARTH DRILLING, e.g. DEEP DRILLING; FIXED CONSTRUCTIONS; MINING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR ASLURRY OF MINERALS FROM WELLS

FIELD: examination of holes by geophysical methods, establishment of geological properties of rock in space near hole, specifically, while studying inhomogeneity of rock mass. SUBSTANCE: invention refers to determination of structural-mineralogical and fluidal models of geological environment with delineation of geological bodies and basins by various structural and lithological indications, to exposure of hydrocarbon deposits in section of hole and to evaluation of reserves. Method includes execution of geophysical examinations and processing of obtained information with evaluation of geological properties and subsequent isolation of intervals of collectors. Rock is modeled as structural framework built by particles charged electrically and forming pore space and integral electric charge of pore canals. Form of presentation of geological characteristics in its petrologic properties depending on integral adsorption processes going on which scale is determined by relation of values of electric charge of pores and mineralization of water saturating pores and hydrocarbon saturation of pores is defined. Integral adsorption processes going on in rock are expressed in changes of electric, acoustic, radioactive properties, content of hydrogen and volumetric density of structural framework of rock carrying hydrocarbons and electrolyte formed in its pore space. Generalized petrophysical models presenting geological characteristics of rock in physical fields of methods of geophysical examinations of sections of holes are established on basis of presentations mentioned above. Natural radioactivity of rock, specific electric resistance of rock, increment of anomaly of natural electric potential relative to natural electric potential of enclosing clays and one parameter chosen from group including time interval of propagation of longitudinal acoustic wave in rock, hydrogen content of rock and volumetric density of rock are found in uncased holes during geophysical examinations of sections of holes. Integral electric charge of pore canals of structural framework of rock, porosity, fractions of general water and water bound in pore space are computed on basis of usage of generalized petrophysical models while processing information continuously obtained along shaft of hole with chosen step by depth. Combination of above-mentioned parameters with measured parameters of natural radioactivity of rock determines geological characteristic of rocks which are indices of structural-mineralogical inhomogeneity of geological environment, its collector properties, hydrocarbon saturation, absolute and phase permeability. EFFECT: increased detailing and authenticity of establishment of geological characteristics of all rocks laying down terrigenous mass, determination of structural-mineralogical and fluidal models of component rocks. 1 cl, 14 dwg, 1 tbl