Study of oil recovery from reservoirs of different void types with use of multidimensional statistical analysis

Abstract

Oil recovery laws that take into account distribution of reservoirs with different void types within the same accumulation. Carbonate field data of development of Tournaisian-Famennian oil accumulation was used. For comparison purposes data of development of the field with similar oil properties but reservoir of clastic grain rock and pore type were used. One injector and neighbor producers were used as components of applied production scheme. The type of reservoir within one development object was determined by several studies including pressure build-up curve processed by Warren-Root method. At the first stage correlation coefficients between injection and production of neighbor well were calculated. Calculation was done for different time and with assumption, according to which correlation coefficient is a quantitative measure of interactions between two wells. It is determined that use of correlation coefficient for pore reservoirs is significantly differ to the character of its behavior for fracture reservoir type. Multidimensional mathematical models that characterize flooding and allow determining producer’s rate were obtained with considered void type. Linear discriminant functions are built with considered void type of reservoir. Analysis of those functions determined that replacement of oil by water in clastic and carbonates porous rocks and carbonate naturally fractured reservoirs follow different scenarios.

Keywords

• complex accumulation
• naturally fractured reservoirs
• pore type reservoir
• oil production law
• components of development scheme
• well interaction analysis
• correlation
• correlation fields
• multidimensional regression analysis
• mathematical models
• factors forming oil rate in different reservoirs
• linear discriminant functions
• authenticity of reservoir detection
• oil rate formation scenarios
• efficiency of pressure maintenance system