Reservoir Control and Oil Geochemistry

By

 Enver Ablia¹, Elena Slivko¹

(1) Geology faculty of Moscow State University, Moscow, Russia

 Doesn’t doubt the power of geochemical information. This data mainly use for genetic conclusions. However, geochemical application for exploration and special for production is still limited. We believe the oil is complex hydrocarbon solution, making interconnected system with rock matrix and contacting water solutions. Oil samples from some West Siberian lithologically screened accumulation fields have been analysed. The ash value flow, capacitor properties and types of cement is observed. Different zones are focused in parallel lines reservoirs pinchout line. In change of structure oils the following is revealed based on bulk data and individual hydrocarbons (HC) distribution. The most appreciable changes are observed in distribution of gasoline HC’s and some other HC’s. The gradient of change on kilometre to the screen (G) was calculated. To clay screen the ratio alkanes/iso-alkanes (G - 0.09) and alkanes/ Cycloalkanes (G - 0.17) decreases. These gradients are well correlated with zones of identical reservoirs distribution. Hexane/iso-hexane quickly varies at the screen (up to 5 km) and further becomes gently sloping. Uniform reduction of benzene concentration is observed to the screen (G - 0.05). The basic features of oil composition change are connected with natural chromatography by effect of reservoir diverse. Various HC’s are subject to various influence of sorption forces on phases border of the rock-fluid. Thus fluids too are not homogeneous at contact with water, each HC thus are dissolved differently. The received results testify that the data of oil composition can be use for of reservoir distribution and optimisation of exploration processes.