The authors present here a computer program (FORTRAN IV) for calculations on eater drive oil reservoir. The program developed in this paper combines the calculations of determining the original oil in place and predicting the reservoir performance, and gives promise of treating a large quantity of these complex calculations with profitable speed and precision. To decide the optimum values of the original oil in place and the water influx in the program, the slope of curves on original oil vs. production time must be calculated, and those values in the case that the absolute value of the slope is minimum will be selected as the optimum value. Successively, the prediction of the field performance is carried out with the optimum values decided.
The vertical distribution of boron has been investigated in marine mudstones sampled in stratigraphic drill cores in the western Aizu district, Fukushima Prefecture, Northeastern Japan. Organic carbon and K2O content were also determined in order to examine a possible interrelationship of these with the distribution of boron. Forty six core samples were collected which are correlated with the Globorotaria-Hopkinsina zonule of the Nishikurosawa stage and Spirosigmoilinella zonule of the Onnagawa stage of Middle Miocene age. Boron was determined spectrophotometrically after decomposing powdered samples in a mixture of sulfuric and hydrofluoric acids and extracting the methylene blue-tetrafluoroborate complex with dichloroethane. The analytical results show that within the range tested the boron content decreases stratigraphically from the lower bed (Nishikurosawa stage) to the upper one (Onnagawa stage). The potential use of boron in conjuction with other parameters for a paleoenvironmental analysis is discussed.