December 04, 2023
Moscow, Russia
November 28-30, 2023
Moscow, Russia
Negotiations with Sinopec Corp.
November 4-9, 2023
Beijing , China
June 2023 г.
Vienna, Austria
83th EAGE Annual Conference&Exhibition 2022
June 2022 г.
Madrid, Spane
The usage of this technique makes it possible to excite seismic vibrations simultaneously by several groups of vibration sources located at different shot points, thereby, increase the productivity of the work. This technique is based on the use of special time-extended (to compensate for the number of accumulations) pseudo-random sweep signals that are uncorrelated with each other. In this case, the generated sweep signals have the same frequency range and duration. To form a Shuffle sweep, the frequency-time base, e.g., an extended linear sweep (up to 60 seconds), is divided into a fixed number of segments of predetermined equal length along the time scale and then randomly rearranged. This random ordering of the frequency-time segments of the Shuffle sweep allows different groups of vibration sources to work different frequency ranges simultaneously.
Application example:
In March 2022, Bashneftegeofizika, with the participation of experts from Spetsgeofizika, conducted work in the Yuzhno-Yamburgskaya area to evaluate the impact of working methods on the productivity of seismic surveys when using different types of sweep signals. The basic possibility of implementing ISS and Shuffle techniques with cable equipment was demonstrated (in the original version of the work on the ISS method, it was planned to be implemented with the Stride cableless system).
An area of 30 square kilometers (2000 shot points) was selected to conduct the experiment and methodology. Four groups of installation of a seismic signal were mined at this site. To mine the area, the type of sweep was selected and the number of sources in the group was determined (see fig. below). Registration was done in continuous recording mode on the Sercel 508XL* (99-second seismic slices). The vibrator control system GDS-II provided the ability to determine coordinates and registration times. Transcriber® software was developed to allow processing of such data.
The following methods were chosen to compare performance:
Slip-sweep (manufacturing method), quasi-linear signal
Shuffle, pseudo-random signal
ISS, linear frequency modulated signal
ISS, Broadsweep Technology.
Characteristics of the compared methods and sweep geometries are shown below.
Comparison of methods:
* Ph/Hour — physical observation per hour |
Data on the performance of each method was obtained from seismic station operators' reports for a given section of the region where 2000 shot points were worked. This figure shows the performance indicators of the methods in their pure form, not taking into account downtime due to weather conditions, refueling, etc. The performance gain with ISS technology is approximately 1.75 times that of Slip-sweep. The performance of Shuffle is twice that of Slip-sweep; as with ISS, the limit on the number of groups per seismic station is 32 groups. |