The textbook discusses the basics of metrology, certification as a form of conformity assessment and standardization in the Russian Federation in accordance with the federal laws "On Technical Regulation" and "On ensuring the uniformity of measurements". Meets the requirements of the federal state educational standards of higher education of the latest generation. For students of higher educational institutions studying in the areas of training 27.03.01 "Standardization and metrology", 27.03.02 "Quality management".

An integrated approach was applied for production enhancement of the upper and lower shaly sandstone reservoirs of the Ignalinsky and Tympuchikansky fields in the Leno-Tunguska oil and gas province of the East Siberian Basin, Russia. The approach includes both comprehensive laboratory studies and a direct strategy of hydraulic fracturing design, as well as solutions to obtain optimum well performance. The approach can be implemented in future prospects and can form part of the strategy for future development in the region. Extensive laboratory research was performed to select the proper fluid for proppant transport that could withstand all the complicated terrigenous conditions within the fields. One of the main challenges was rheological suitability of the fluid at low reservoir temperatures. The laboratory studies were important for identifying the best fluid for fast fracture cleanup while optimizing the sand-carrying capacity of the fracturing fluid. The hydraulic fracturing design incorporated calibrated petrophysical and geomechanical analysis with actual fluid rheology characterization taken from laboratory test results. The laboratory work confirmed that the reservoir rock was water sensitive, with a significant presence of clay minerals including kaolinite, montmorillonite, and montmorillonite mixed with illite. A new generation of clay stabilizer was used to address this sensitivity. In addition, an enzyme breaker was used with the objective of effectively breaking the fracturing fluid at low reservoir temperatures. The fracturing operations that were performed during two winter campaigns resulted in high starting and operating production rates. The treatment designs incorporated a linear gel pre-pad stage prior to the crosslinked pad stage in an effort to extend fracture half-length while reducing the risk of the fracture growing in height into overlying gas-saturated layers. The results of the design efforts were analyzed using logging and fracture treatment data, which demonstrated that the design was effective in avoiding the gas-saturated formation. Overall, 23 hydraulic fracturing operations were done in five wells at Ignalinsky and Tympuchikansky fields for the B10 and B13 formations. Production results were analyzed, and further optimization paths were identified. The study breaks new ground in enhancing the hydrocarbon extraction from low-temperature shaly sandstones with mixed wettability, not just with terrigenous reservoirs within the above-mentioned fields, but also with other reservoirs of a similar geological context, primarily the Leno-Tunguska oil and gas province of the East Siberian Basin, Russia. This is especially important in view of the depletion of oil reserves in Western Siberia and the growing interest in the development of hydrocarbon fields in Eastern Siberia.

Yuri Korchagin field, located in the Russian sector of the Caspian Sea, is one of the largest field on the Caspian shelf with proven reserves stand at 29 million tons of oil and 63 billion cubic meters of gas. Since the beginning of commercial operation, in the spring 2010, the field production passed eight million tons of oil. The operator company conducts development of Yu. Korchagin field by a system of horizontal wells with a length up to 8000 m, from a fixed offshore ice-resistant platform, installed in the dome area of the structure. The main challenges in the field development are associated with premature water and gas breakthroughs at high permeability intervals of horizontal wells. Currently, as a result of the sharp increase in the field water cut, the oil production is constrained due to the existing limitations on volume of produced water that can be utilized in the conditions of the offshore field. Two water-injection wells were drilled and commissioned to utilize produced formation water into the aquiferous zone of the carbonate reservoir. In order to restore and increase the injectivity factor, small-volume acid treatments are carried out yearly on the carbonate reservoirs in the lower horizontal sections of the water-injection wells. Since 2014, more than 20 matrix and hydrochloric acid treatments were performed with application of acid systems of different compositions and volumes. In some cases, the wells injectivity increase after matrix acidizing treatments with traditional acid systems was below expectation, demonstrating limited and short-term effect. Therefore, with constantly increasing volume of produced water at the field, it was required to increase the frequency of acid treatments to maintain the appropriate level of injectivity of the water-injection wells. The additional treatments are associated with significant time and financial costs because of the offshore platform standby and production suspension. The need exists to improve efficiency of acid stimulation treatments performed in the field to achieve sustainable increase in injectivity index of existing wells. The purpose of this study is to analyze acid stimulation treatments carried out on carbonate reservoirs of the horizontal water-injection wells in 2014-2017, evaluate the efficiency of the treatments with different acid systems to change the injectivity factor, discuss the prospects for their application in Yu. Korchagin field and formulate recommendations for further efficiency improvements of acid stimulation treatments in the field.

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