ABSTRACT: Integration of 4-D seismic with other reservoir data for light oil steam flood monitoring, Minas oil field, Sumatra, Indonesia

Seffibudianti, Michael D. Blancher, Hari Primadi, Cedric C. Cease, Faizil Fitris, B.J. Rinaldi , (1) PT. Caltex Pacific Indonesia, Pekanbaru, Riau, Indonesia

A 4-D seismic program has been implemented to monitor steam and heat movement at Minas Oil Field, Sumatra, Indonesia. The initial phase of the Minas Light Oil Steam Flood project has been underway since early 1999, with steam injection into 7 hexagonal patterns. The Minas oil field produces from a stratified sequence of nearshore marine sands of the Miocene Sihapas Formation. At the Light Oil Steam Flood site, there is over 200 ft. of pay, with five main pay zones present in each well. Steam is simultaneously injected into multiple sands, and production from all zones is co-mingled.

An aggressive reservoir monitoring program has been implemented to assist in tracking steam and fluid movement. The key tools are 4-D seismic, temperature logs and Pulsed Neutron Capture (PNC) logs in observation wells. The 4-D seismic program consists of an initial baseline survey followed by monitor surveys recorded twice yearly. The temperature logs are recorded in observation wells monthly, with PNC logs recorded every second month. This monitoring program augments the recording of a significant volume of production and injection data, including measurements of temperature, pressure, fluid composition and rates at the surface facilities.

All of the monitoring information is limited, both by the resolution of the tools and by the spatial and/or temporal sampling of the measurements. This paper describes how integration of 4-D seismic observations with well log monitoring data in a comprehensive reservoir model leads to a greater understanding of the fluid changes in the Minas reservoir.

AAPG Search and Discovery Article #90913©2000 AAPG International Conference and Exhibition, Bali, Indonesia