Estimering av usikkerhet ved undergrunnens poretrykk ut ifra trendlinjevariasjoner

• Main Authors: Pei, Jianyong, Wessling, Stefan
• Format: Patent
• Language: Norwegian
• Published: 27.12.2021
• Subjects: CALCULATING; COMPUTING; COUNTING; DETECTING MASSES OR OBJECTS; EARTH DRILLING; EARTH DRILLING, e.g. DEEP DRILLING; ELECTRIC DIGITAL DATA PROCESSING; FIXED CONSTRUCTIONS; GEOPHYSICS; GRAVITATIONAL MEASUREMENTS; MEASURING; MINING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR ASLURRY OF MINERALS FROM WELLS; PHYSICS; TESTING

Disclosed is a method for estimating a pore pressure of an earth formation penetrated by a borehole and an associated uncertainty. The method includes: conveying a carrier through the borehole; performing formation measurements at a plurality of depths in the borehole using a downhole tool coupled to the carrier; defining a first depth interval and a second depth interval deeper than the first depth interval, the first depth interval including a first set of formation measurement points and the second depth interval including a second set of formation measurement points; establishing a plurality of trendlines of depth versus formation measurements using a processor with each trendline in the plurality of trendlines extending from a point in the first depth interval through a point in the second depth interval; and calculating a pore pressure line and associated uncertainty using the plurality of trendlines.