Rock samples from four wells were examined in the Santa Maria Basin, Santa Barbara County, CA. The intervals were selected to pinpoint known and unknown rock intervals in these wells. Electric logs were taken in three of the four well sections examined. The samples were examined both lithically and paleontologically, for the purpose of knowing their lithological and paleontological characteristics.
A percentage lithological study was made, and a lithic chart was prepared displaying the rocks found in the samples. The samples also were processed for paleontology and studied for fossil content. Index fossils found included benthic and pelagic foraminifera, radiolaria, diatoms, and algal cysts. Results were plotted on fossil distribution charts, and the index fossils plotted on range charts. Because of the refractory nature of the samples, some were not as productive as index fossils as they could be, but because of earlier work the researchers were able to get enough information to do the job.
Project Results
The major achievement has been to use biostratigraphy to sort out and identify the productive section from the non-productive section in a basin proven to contain hydrocarbons.
Benefits
The benefits to industry are many. By identifying the productive section, an operator can drill more intelligently into the target section. This reduces risk by narrowing down the target for production. This increases production, because fewer wells have to be drilled, and in a shorter time to find the target interval. This reduces environmental impacts by eliminating needless drilling where the target interval is unknown, even in a proven field.
Project Summary
By using paleontology, the researchers were able to correlate from the known sections to the unknown and find similar productive zones in the unknown. This was notable in the Triton No. 10 Blair and OTEC No. 1 Boyne wells.
Both benthic (bottom dwellers) and pelagic (floating specimens) provided age and environment information to find more oil. This was significant in the OTEC No. 1 Boyne well.
By using lithology, researchers were able to determine lithic characteristics of formations as well as determining the ages of the sediments (OTEC No. 1 Boyne well).