IMPROVING THE RELIABILITY OF THE THREE-DIMENSIONAL GEOLOGICAL BASIS OF COMPLEX DEVELOPMENT TARGETS

This article proposes a new method for identifying different groups of reservoirs when constructing a three-dimensional geological and hydrodynamic model of the target. Productive formations of the Bajocian and Bathonian stages of the Jurassic system of the Kalamkas field were selected as the object of study. This field is tectonically associated with the northern part of the North Buzachinsky arch, located at the northwestern end of the Turan plate. It was noted that these productive deposits have a complex geological structure, due in lithological terms to uneven alternation of sand-siltstone and clay rocks. In addition, four different reservoir classes are identified within each tier, which are characterized by their own permeability-porosity correlation relationships. As a result, for reliable construction of the filtration field, it is necessary to determine the distribution zones of each of the identified reservoir classes within the reservoir. This is due to the fact that due to the different filtration field, the development of reserves from each group of reservoirs will occur unevenly both in area and in section. In this regard, the integrated Flow Zone Indicator (FZI) was evaluated using the results of laboratory core studies. In order to obtain a continuous FZI parameter for wells without core sampling and laboratory analysis, the results of laboratory studies were compared with the results of well geophysical studies (well logging). As a result, analytical dependence of FZI and log data was obtained. Based on this analytical dependence, new three-dimensional models were constructed and zones of distribution of different groups of reservoirs were identified. To verify the obtained results, the synthetic FZI curve calculated from the obtained analytical relationship was compared with the FZI estimate based on the results of laboratory core studies. It is concluded that the synthetic FZI curve is consistent with the FZI estimate based on the results of laboratory core studies and, therefore, the proposed approach can be used when performing work related to 3D modeling.