Method and apparatus for inverting formation wave impedance using DAS borehole seismic data
AssigneesChina National Petroleum Corporation, BGP Inc., China National Petroleum Corporation
InventorsYanpeng Li, Zhidong Cai, Fei Li
Life of this patent
Estimating the term…
Abstract
A method for inverting a formation wave impedance using DAS borehole seismic data, including: acquiring an initial magnitude at a time window after the initial arrival time of seismic wavefield data in a well; mapping the initial magnitude to a relative wave impedance; and correcting the relative wave impedance to obtain an inverted wave impedance. Also provided are an apparatus for inverting a formation wave impedance using DAS borehole seismic data, a device, and a computer-readable storage medium.
Claims13
A method for inverting formation wave impedance using DAS borehole seismic data, comprising:
- obtaining a first arrival amplitude of borehole seismic wavefield data, wherein the first arrival amplitude comprises a root mean square amplitude or an average amplitude of the borehole seismic wavefield data within a time window after a first arrival time, wherein the borehole seismic wavefield data are obtained by using an optical fiber DAS acquisition instrument;
- mapping the first arrival amplitude to relative wave impedance;
- and
- correcting the relative wave impedance by the following formula to obtain inverted wave impedance:
- IDAS=a×Ir+b,
- wherein, IDAS is the inverted wave impedance, Ir is the relative wave impedance, and a and b are correction coefficients;
- and
- wherein, the correction coefficients a and b are determined through the following steps:
- calculating wave impedance of a corresponding well section through existing well-logging data;
- making a crossplot of the wave impedance with the calculated relative wave impedance;
- and
- obtaining the correction coefficients a and b through linear fitting.
A device for inverting formation wave impedance using DAS borehole seismic data, comprising a memory, a processor and a computer program stored in the memory and capable of operating on the processor, wherein the processor, when executing the computer program, implements the following steps:
- obtaining a first arrival amplitude of borehole seismic wavefield data, wherein the first arrival amplitude comprises a root mean square amplitude or an average amplitude of the borehole seismic wavefield data within a time window after a first arrival time of borehole seismic wavefield data, wherein the borehole seismic wavefield data are obtained by using an optical fiber DAS acquisition instrument;
- mapping the first arrival amplitude to relative wave impedance;
- and
- correcting the relative wave impedance by the following formula to obtain inverted wave impedance:
- IDAS=a×Ir+b,
- wherein, IDAS is the inverted wave impedance, Ir is the relative wave impedance, and a and b are correction coefficients;
- and
- wherein, the correction coefficients a and b are determined through the following steps:
- calculating wave impedance of a corresponding well section through existing well-logging data;
- making a crossplot of the wave impedance with the calculated relative wave impedance;
- and
- obtaining the correction coefficients a and b through linear fitting.
A non-transitory computer readable storage medium, wherein the storage medium stores an instruction, and the instruction, when running on a computer, cause the computer to execute the following steps:
- obtaining a first arrival amplitude of borehole seismic wavefield data, wherein the first arrival amplitude comprises a root mean square amplitude or an average amplitude of the borehole seismic wavefield data within a time window after a first arrival time of borehole seismic wavefield data, wherein the borehole seismic wavefield data are obtained by using an optical fiber DAS acquisition instrument;
- mapping the first arrival amplitude to relative wave impedance;
- and
- correcting the relative wave impedance by the following formula to obtain inverted wave impedance:
- IDAS=a×Ir+b,
- wherein, IDAS is the inverted wave impedance, Ir is the relative wave impedance, and a and b are correction coefficients;
- and
- wherein, the correction coefficients a and b are determined through the following steps:
- calculating wave impedance of a corresponding well section through existing well-logging data;
- making a crossplot of the wave impedance with the calculated relative wave impedance;
- and
- obtaining the correction coefficients a and b through linear fitting.
Dependencies are inferred from the claim text.