Abstract

Hungarian Oil and Gas plc. (MOL) decided to carry out a more than 1000 square km 3D survey over the mature age Szeged-Algyö Field in 1999. Data acquisition and processing were carried out by Geophysical Services Ltd. (GES). This case history shows how MOL and GES cooperated and interacted in planning and managing of this complex 3D project.

During the preparation and operation phases of the survey they had to manage several environmental protection and public concerns, while keeping an eye on the geological objectives of the project.

The continuous real time information flow and feedback - between the field crew and quality control organizations of the Client and Contractor - could manage the challenging field conditions. Regular field audits and team meetings monitored the required quality and evaluated the process performance. The improved interaction resulted in smooth operation and good quality data satisfying the Client's requests with zero impact on the environment and public interests.

Introduction

The Szeged-Algyö Field is the largest hydrocarbon accumulation of Hungary. The oil and gas pools were discovered in 1965 and within two years the CH reservoirs were set on pipe.

The producing field is located partially underneath the cities Szeged and Algyö having an improved infrastructure and more than 180 000 inhabitants.

The field was explored and developed by extensive drilling activity mainly in the 60s and 70s. The annual production of the Szeged-Algyö field at its peak time - in the 70s and early 80s - reached 7.5 MBBL oil and 100 Mcf gas. Although more than 1000 wells were drilled into the reservoirs to date, complex stratification patterns governed by the original lacustrine deltaic depositional environment prevented unambiguous correlation and spatial definition of the sandstone bodies.

By the end of the 90s the declining production of the field necessitated exploration of the forecasted small size satellite fields around the main producing field.

Planning and Pre- Szeged and Algyö cities, the Tisza and Maros rivers with their protected wetland forests and large permitting fishing lakes located North to Szeged were the main challenges that 3D seismic had to face to (See Fig. 1). During the pre-permitting phase the work program - containing the theoretical 3D network - was submitted to the competent environmental protection organizations and to other local authorities to ask for their preliminary opinion.

Besides the strictly protected exclusion zones there were two main temporal restrictions which basically determined the further planning steps: BLOCK 1 - - FORUM 6 561

LARGE SCALE 3D SEISMIC DATA ACQUISITION ON AN ENVIRONMENTALLY SENSITIVE AREA IN CENTRAL EUROPE

  • because of the spring time breeding season and passage of bird

This content is only available via PDF.
You can access this article if you purchase or spend a download.