Marine operations

Surveying marine seismic data:  providing qualified services in shallow and deep waters

-Cooperation in 2000pc project in a region with length of 6000 kilometer in Persian Gulf and See of Oman

Persian Gulf includes the greatest global oil and gas reservoirs.   2000PC project which was fulfilled as per contract between Iran National Oil Company as one party and Mostazafan Foundation’s Energy Group and Norex Group (a Norwegian Company) as the other party,  covers all coastal waters in Iran and highly qualified 2D seismic operations were done. Accordingly,  a concentrated network with distance of 2*2 km was obtained from seismic lines and subsequent surveys were performed.  Oil Exploration Operations Company played a key role in mentioned process.

The value of this project was 105,000,000 million dollars which lasts for two years and completed in June 2002.

Hereunder is a list of OEOC marine seismic projects. 

Seismic Operations in Shallow Coastal and Swamp Waters

Geophysics department has required capabilities for providing geophysical services including 2D & 3D seismic operations for qualified seismic data survey in planes, mountains, transition zones and even on sea.

Services of this department are:

• Performing gravimetry and magnetometry operations by modern equipments
• Performing 2D and 3D land seismic operations through subtle and modern equipments
• Performing 2D and 3D land seismic operations in swamplands, shallow waters and marine areas
• Processing 2D and 3D seismic data by advanced software and hardware
• Engineering services for fulfillment of civil, mine and other studies

Multi-component Land and Marine Seismic Operations 

Geophysical Equipments:

The main secret of our success is continual improvement of equipments along with permanent development of personnel’s knowledge.

Oil Exploration Operations Company is always following a specific plan in updating its equipments and software that are used in operational works. This company is recently employing modern seismological equipments including UL428Sercel and UL408Sercel recording systems and 65 Nomad vibrators in its projects.

Aforesaid recording systems are more qualified than previous ones. Some of their specifications are as follows:

• Existence of a LINK which a complete units of seismological cables and numerous separate electronic channels with specific interspaces. These units are very efficient.
• Seismic Areal Network is used in these equipments instead of telemetric traditional system. All parts of this system are nodes which are active on a seismological network and are connected with a recording device. Such systems are benefited from a multimedia network including laser, radio, cable and etc. which are providing appropriate solutions for complicated arrays.
• Usage of advanced software:

Usage of modern software (Seismic Network Software) for controlling modern equipments of aforesaid machineries. This software can prepare Single-Component or Multi-Component recording through 3D methods and has very considerable capacity for registration of seismic data in big projects.

65Nomad vibrators which are employed in this company are providing required conditions for production in different geographical conditions with high security and less maintenance requirements.

VSP Operations

Vertical seismic profiling (VSP) is a set of well’s registered seismographs.

Daily measurements including Electric Logs and Rock Cuttings are providing limited information about well’s casing.

Although surface seismic profiling provides required conditions for measuring larger areas and collects more information from subsurface horizons, these data are some limitations in resolution and etc. VSP may provide information which is appropriate to calibrating data gathered from two mentioned methods.

Usage of energy source geometry/ receiver in VSP technique creates appropriate method for aforesaid purposes.

Oil Exploration Operations Company has adequate experience in providing VSP services as well logging operations which include required specifications for various geophysical surveys including modeling, designing, data collection and processing.

Exact time/depth relation and speed of waves flow in different subsurface layers can be calculated through Downhole travel – time measurements and employ their results for calibrating surface seismic and well logging data. These services includes following methods:

• Stationary  Source  Velocity  Survey with Near- Wellhead Source
• Vertical Incidence Velocity Survey (Moving Source Directly above Downhole Receiver(s) in Deviated Well).

Reviewing, Processing and Explaining Data

Processing seismic data is necessary for connecting geophysical data survey and explaining that data. This progress required high speed and accuracy. Our purpose in OEOC Company is to process geophysical data in order to provide the most accurate and obvious image from subsurface structures.

This company can process 2D, 3D and 4D seismic data of lands, transition zones and marine area by employing a set of professional processing software.

ProMaz, GeoCluster and +GeoVecteur are among software that are used in processing department of OEOC for processing 2D and 3D seismic data of land and marine areas. VSP data may also be used in accordance with employer’s inquiry.

One of the distinctive aspects of OEOC processing center is designing and processing sequences and parameters for solving problems of a seismic line or part of 3D Cube.

Accordingly, various processing methods are employed for quality control and representing related results. We try to provide final results with high resolution and true relative amplitude. Reciprocal cooperation of processing and interpreting teams provides required conditions in order to develop conformity of final results with geological criteria.

Hereunder are services of OEOC processing department:

–  Processing 2D and 3D land and marine seismic data

–  Reviewing seismic data

–  Preparing seismic profiles

–  Preparing well logging diagrams

–  Interpreting 2D and 3D land and marine seismic data

Other used software:

–  Focus Software (data processing)

–  Seisfile Software (digitalizing data)

–  Logfile Software (digitalizing data)

–  SpaMedia (compacting and rewriting data from magnetic bonds on DLT)

–  Magma (compacting and rewriting data from magnetic bonds on DLT)

–  Tigress (Interpreting)

–  Hampson Russel (Seismic Inversion)

–  Odegaard (Seismic Inversion)