ABSTRACT

A 3-D seismic survey utilizing innovative techniques and technology has been performed in an extremely challenging transition zone program acquired in the Malacca Strait region of Sumatra, Indonesia.

Although this project was nearly antipodal to the Gulf Coast, it is an excellent example of salt water transition zone and marsh 3-D seismic data acquisition. In addition to heavy jungle, the project crossed water with depths of up to 50 meters and tidal currents of five to seven knots. These conditions would normally have dictated the use of two different acquisition systems for the project; a land/marsh system and a bay-bottom system. Utilizing two systems introduces several problems to the acquisition contractor. Capital equipment expenditures increase, because the contractor must either rent or purchase two systems. The contractor also faces increased logistics in supporting two systems and training personnel in the use and deployment of two systems. The end user may also face compromises, because he must merge data sets from what are essentially discrete surveys recorded by two different systems. This may introduce geometry errors, inconsistent data quality, and increased data processing costs.

Geo-X System Ltd.'s ARAM24 system offered technology developed in the Gulf Coast of Texas and Louisiana that enabled the contractor to use a single system on the entire project, thereby eliminating the logistical and economic difficulties associated with the two system approach.

The solutions adopted in response to this very difficult acquisition problem offer a comprehensive approach to seismic data acquisition in the transition zone environment.