ON THE SEPARATION OF SIMILAR FACILITIES BASED ON THE APPLICATION OF CLUSTER ANALYSIS
Authors: Vefa Suleimanova Vefa Suleimanova , Nurlan Jabizade Nurlan Jabizade , Sevil  Zeynalova Sevil  Zeynalova 
Published: March 2022

As in all fields of science, in geology it is very important to study the degree of similarity or diversity of deposits and their layers [1,2].
The similarity or diversity of the deposits should be realized using the values of their complex parameters (collector indicators, physico-chemical properties of formation fluids, energy properties, etc.). In this case, the field or layer is considered a multidimensional object and is classified using specially designed models.
Classification methods play a key role in creating the geological basis of oil and gas fields. Therefore, it is very difficult to compile development projects for each of them. Here it is convenient to carry out geological-technological measures not in separate exploitation objects, but in groups consisting of similar objects.
There are many methods of classification in geology. The most commonly used are cluster, factor and discriminant analysis. In the article, with the help of cluster analysis, a grouping operation of similar objects was carried out on the example of block IV of the Neft Dashlary field. When applying cluster analysis, it should be checked whether there is a relationship between the data carrier parameters.When there is a dependence between the parameters, some errors occur as a result of the classification.Therefore, this method can be used as an express method.
Due to the time constraints in the development of offshore fields, maximum oil must be produced in a relatively short period of time. For this purpose, both II and III impact methods should be applied to the fields, the well network should be compacted, and it is necessary to use mathematical methods to separate the exploitation objects at the cross-section of the field and to separate the objects that can be developed together.
Neft Dashlary belongs to the Absheron archipelago, located in the Caspian Sea, and is the second most potential field in terms of hydrocarbon reserves after the Guneshli field. The field was opened in 1949. It is divided into 6 tectonic blocks by numerous faults. According to the information received, 81% of the remaining recoverable oil reserves belong to blocks IV and V.
The maximum thickness of the studied sedimentary complex was recorded in the area of V tectonic block 3350 m according to well 1918. Extensive research has been carried out in the Lower Pliocene (Productive strata) sediments, which, like other fields in the Absheron oil and gas district are important for industrial oil reserves.
The lithological composition of the Productive strata (lower Pliocene) consists of the replacement of sand, sandstone, siltstone and clay, as the Absheron oil and gas district. The thickness of these sediments is up to 2400 m.
Since the beginning of development, 1804 wells have been drilled in the field, of which 338 wells are in operation. Injection method is used to prevent the formation pressure in the field from falling. The process of impact with water began in 1953, and a certain amount of additional oil production was obtained [3, 4].
The IV tectonic block of the Neft Dashlary field was involved in the research. Development of tectonic block IV began in 1951 with the commissioning of the horizon QA-2a. 18 productive horizons have been developed in the block. Given that each of these 18 facilities is in the final, that is stage IV of development, the study of the geological features of the effective completion of development is a very important problem.
Since the beginning of development, 32693.0 thousand tons of oil and 2907.9 million m3 of dissolved gas have been extracted from the block. The number of drilled wells is equal to 369. The number of operating wells is equal to 71. The current oil recovery factor for the block was 0.414, and the last oil recovery factor was 0.492 [5, 6, 7, 8].
VIIa, VIII, IX, X and FLD IV are the basic horizons of the block. 20.5% of the oil extracted from this block falls on these horizons.
As for the analysis of the well fund, according to the current data, 23 exploration, 319 exploitation and 27 water injection wells have been drilled in the studied area. There are 74 wells in the general exploitation well fund, of which 71 are in operation and 3 are inactive. Of the existing production wells, 2 are operated by fountains and 69 by gas lifts. 4 wells are working in the injection [9, 10]. Due to certain geological and technical reasons, 280 wells (254 wells from the exploitation fund, 26 wells from the pumping fund) have been liquidated, and 11 wells are awaiting liquidation from the exploitation fund.
18 oil exploitation facilities are separated in the IV tectonic block of Oil Rocks. At this time, it is very difficult to develop separate projects for any facility. Therefore, it is considered expedient to develop measures aimed at increasing the efficiency of development not for separate exploitation facilities, but for a similar exploitation facility, and classification methods are used [11].
Keywords: deposit, block, reserve, well, injection, cluster analysis, group, geological-technological, classification.