Method for removing low-frequency noise from records with data impulse

Patent · Tue Dec 05 00:00:00 EST 1989

OSTI ID:6916284

Leland, F

This patent describes a method for Separating high frequency impulse data of known generally periodic character in a signal recorded in a borehole logging operation from low frequency noise superimposed thereon. It comprises: storing the recorded signal; applying median filtering to the stored signal, such that the impulses are removed from the median-filtered signal. The step of applying median filtering to the stored signal comprising the further steps of: sampling the signal at regular intervals of time; defining the length of a data window consisting of a predetermined number of samples of the signal, the number being predetermined in accordance with the known generally periodic character of the signal, such that no one data window includes more than one impulse; successively ordering samples of the signal in the windows by amplitude; employing the median-valued sample in each window as the corresponding value of the median-filtered signal; and subtracting the median-filtered signal from the stored signal.

• Assignee: Mobil Oil Corp., New York, NY
• Patent Number(s): US 4885772; A
• Application Number: PPN: US 7-145014A
• OSTI ID: 6916284
• Resource Relation: Patent File Date: 19 Jan 1988
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
03 NATURAL GAS
WELL LOGGING EQUIPMENT
SIGNAL CONDITIONING
DATA PROCESSING
EXPLORATORY WELLS
NATURAL GAS DEPOSITS
NOISE
PETROLEUM DEPOSITS
PULSES
EQUIPMENT
GEOLOGIC DEPOSITS
MINERAL RESOURCES
PROCESSING
RESOURCES
WELLS
020200* - Petroleum- Reserves
Geology
& Exploration
030200 - Natural Gas- Reserves
Geology
& Exploration