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Cost-effective geophysical technology for petroleum exploration in non-seismic areas (CEHEG)

Objective

Objectives and problems to be solved:
Significant European oil reserves are contained in geological structures where conventional seismic exploration techniques are largely unsuccessful. Examples of this include Southern Italy, Greece, Albania, and the former Yugoslavian republics. However, complex but prospective structures can be characterized on the basis of electrical resistivity contrasts between the various rock units. An excellent example of this is the over thrust zone of Southern Italy, where the application of magneto telluric (MT) techniques has aided substantially in the identification of the large oil fields of the Val d'Agri. The objective of the present project is to extend existing MT technology to areas where the structures are even more complex, and where the acquisition and processing of magneto telluric data present significant problems.
Specifically, issues addressed within the two-year program are:
1. Advanced processing techniques, which will function in areas of high industrial noise, and
2. Improved sub-surface imaging techniques applicable to near-vertical structures with a strong degree of three-dimensionality. An area in NW Greece will be used as a test area, where limited well control, very poor seismic data quality combine with attractive stratigraphy, on-strike oil production in Albania, and local oil-shows to present an intriguing but technically-difficult oil exploration target.
Description of work:
The research carried out concerns the validation of a method (i.e. MT) which is cost effective, for characterizing some of the most significant structures, (i.e. near-vertical structures, including salt domes) which could, potentially, host large oil reserves.
Examples of the type of petroleum resource assessment issues that are addressed using the MT approach include:
1. Mapping reservoir zones characterized by a significant resistivity contrast with respect to the enclosing strata;
2. Characterizing potentially oil-bearing structures (e.g. positive structures in carbonates of the Ionian Platform);
3. Step-out well targeting;
4. Mapping reservoir limits for volumetric estimates of resource capacity.
This project will address its goal by completing three main tasks:
1. Develop and test new high resolution MT processing and interpretation software to resolve features relevant oil-bearing structures;
2. Acquire modern MT data in an area with well and other geophysical control;
3. Process and interpret these data, integrating them with well data and other geophysical data to demonstrate a valid and cost-efficient methodology for oil exploration in these difficult environments.
Expected results and Exploitation Plans:
1. Implementation of the state of the art inversion code in two and possibly three-dimensional modelling of magneto telluric data;
2. Reduction of the time necessary to evaluate the dimensions of the hydrocarbon reservoir by using newly developed acquisition, processing and interpretation techniques;
3. Validation of the proposed geophysical method in exploiting difficult geological structures;
4. Transfer of knowledge to an end-user in the petroleum industry;
5. Publication of the results in scientific journals.
Actual outcome: 1. a fully tested code of multistation robust remote reference processing of magnetotelluric (MT) time series data for calculating the transfer function of the time series;
2. a set of 99 (ninety nine) MT soundings in an area of complex geology and rough topography;
3. a fully tested state of the art inversion code for two and three-dimensional modelling of magnetotelluric data;
4. decrease the time of an MT survey acquiring 99 soundings (including repetitions) in an area of rough topography in twenty days with two MT groups;
5. minimize the time to the first computed model of the area of study to almost real time since the first models were produced during the field survey;
6. validation of the magnetotelluric method in exploring difficult geological structures;
7. correlation of the magnetotelluric geophysical method with other geophysical methods.

Funding Scheme

CSC - Cost-sharing contracts

Coordinator

ARISTOTLE UNIVERSITY OF THESSALONIKI
Address

54006 Thessalonki
Greece

Participants (2)

ENTERPRISE OIL EXPLORATION LTD
Greece
Address
Kifissias Ave. 90
15125 Athens
GEOSYSTEM SRL
Italy
Address
Viale Abruzzi 17
20131 Milano