Vol 3, No 2 (2021)
- Year: 2021
- Articles: 10
- URL: https://vestnik-ngo.kz/2707-4226/issue/view/4362
- DOI: https://doi.org/10.54859/kjogi.202132
Full Issue
Articles
Deep oil. Offshore fields in the Gulf of Mexico in the Norflet Formation. Development history and prospects
Abstract
The second part of the article on deep-water deposits in the Norflet formation in the Gulf of Mexico discusses the history of discoveries as a result of the implementation of the largest geological exploration project as well as the project for the development of discovered fields implemented by Shell.
The history of the Appomattox field discovery is discussed in more detail. This discovery played a key role in the entire history of this project, becoming the trigger for the transition to an unprecedented pace of exploration for ultra–deep horizons in ultra-deep water (in total – over 10 km).
Prospects for further E&A activity for Norflet formation in the Gulf of Mexico considered in the final part.
3-26
Forecasting oil and gas saturation of the section based on the results of seismic survey interpretation using innovative methods on the territory of the Republic of Kazakhstan
Abstract
Seismoacoustic entropy analysis – (SAE-analysis) and the method of frequency compositions – (MFC) are methods of seismic exploration aimed at solving problems of direct search for hydrocarbons based on the results of seismic exploration in promising areas. Both methods use the seismoacoustic response of a hydrocarbon deposit when interacting with the incident wave front as a search criterion. The location of the deposit is determined through dynamic processing and statistical analysis of the spectral characteristics of the wave field. The article presents the results of the forecast of oil saturation by the methods of MFC and SAE-analysis on the territory of Kazakhstan.
27-41
Justification for application of in-situ combustion method at high-viscosity oil fields
Abstract
The article describes one of the methods of enhancing oil recovery, the experience of its application, including global, and the design of the development (using 3D reservoir simulation) with the arrangement of the pilot area, taking into account the peculiarities of the method.
42-53
Abnormally high reservoir pressures in areas with a degraded energy state
Abstract
Nowadays, in the Uzen and Karamandybas oilfields most of the developed objects show decreasing reservoir pressure. Therefore, there is a need to consider opportunities for increasing the efficiency of the existing system for maintaining reservoir pressure for specific identified areas.
This article proposes an approach for a detailed analysis of the current energy state of certain areas through hydrodynamic tests of injection wells in non-stationary filtration modes. The reasons for the occurrence of abnormally high reservoir pressures are presented on the examples of wells, and possible ways to solve them are proposed.
54-60
Application of biomarkers and oil fingerprinting for genetic classification of oil families and prediction of oil migration pathways in Nuraly field
Abstract
This paper presents the interpretation of the results of biomarker analysis and oil fingerprinting of all producing wells (36 samples) of Nuraly field for genetic typing and fluid communication assessment within the field, followed by predicting the hydrocarbon migration pathways. According to the biomarker study, it was revealed that the oils of central and western Nuraly have genetically different origins, and the petroleum accumulation in the southern part of West Nuraly was formed by the continuous secondary migration of HC from the northeastern and northwestern directions. Oils from central Nuraly field have higher thermal maturity and lower density than those of western Nuraly do. The thermal maturity of samples from Central Nuraly decreases from the northeastern part of Nuraly towards the southwestern part, which may also attest to hydrocarbon migration pathways. The presence of gas caps in the northeastern part of Central Nuraly may be due to their high thermal maturity.
61-75
Improving the quality of recycled water by pulsed electromagnetic treatment
Abstract
The relevance of this work is of exceptional importance and widespread use in the technological processes at most industrial enterprises, including oil refineries. Industrial enterprises of the oil industry are subject to strict control for environmental protection, water consumption, quantity, and quality of the discharged wastewaters. This paper presents the data on the treatment of circulating water before the section of clarification by the method of reverse osmosis with the use of an electromagnetic treatment device. The authors have manufactured a pilot reverse osmosis plant with the capacity of 0.370 m³/h, the permeate yield (purified water) being 0.3 m³/h, the concentrate discharge being 0.07 m³/h. The test bench operates as a closed circuit, i.e. the permeate and brine are returned to the original container. A process flow sheet for the purification up to standards, meeting the requirements for the make-up water, as well as a technical assignment for designing circulation water supply systems, have been developed.
76-83
Comparative tests of fly ash powder as solid demulsifiers
Abstract
This work investigates the effectiveness of fly ash particles as a solid demulsifier for destabilizing an oil-water emulsion and effectively removing water. The size of the fraction in the used solid powder does not exceed 40 microns in diameter. The demulsifier consists mainly of hematite (Fe2O3) and corundum (Al2O3) phases. The introduction of fly ash into the oil emulsion leads to demulsification of water from oil. The dosage of the powder ranged from 0.1 to 1 g. An increase in the dosage of fly ash leads to a rapid discharge of water from the emulsion. The study identifies the demulsifying properties of fly ash powder. Also, upon redispersion of demulsified samples, no re-emulsion was observed, as a result of which, it can be assumed that fly ash powder can contribute to deasphalting of oil-water emulsion. Reuse of industrial waste is an important method for improving the ecological state of the country.
84-90
Durability of cement stones in injection wells
Abstract
Cement stone is the “weakest component” of the wells, it is easily destroyed when working inside the casing and is vulnerable to the action of most formation fluids. In injection wells, under the action of water injected into the reservoir, intensive leaching of the cement stone occurs, which leads to its complete degradation after several years of well operation. The consequence of this is the injection of fluid into other formations and increased corrosion of the casings. Analysis of the field experience of injection wells showed that inter-reservoir crossflows result in cement stone complete collapse in 4-6 years, while in production wells it retained its properties after 20 years.
Theoretical consideration of the leaching corrosion process made it possible to determine the main directions of reducing the corrosion rate, aimed at improving the structural characteristics of cement stone. Among these, a decrease in the initial water-content and optimization of the porous structure should be optimized.
Analysis of the loads acting on the cement sheath in wells showed that during perforation, hydraulic fracturing and well drilling for deepening, the stresses arising in the cement stone exceed its strength characteristics. Therefore, it is advisable to use «reinforced» and «self-healing» cements to minimize these negative effects.
91-98
Controlled deep perforation by radial drilling of channels with the "Perfobur" technical system to intensify the reservoir inflow
Abstract
The paper presents a technology for controlled deep penetrating perforation using the Perfobur technical system to intensify inflow by drilling radial channels 69 mm in diameter, up to 25 metres in length. This technology was first applied to a carbonate reservoir in the Bashkirian tier, characterised by high heterogeneity and close proximity of bedrock water.
An adjacent well, close to the acid fracture well, with identical reservoir properties, was selected. Well "A" was acid fractured and well "B" was drilled using Perfobur technology with two directional channels, each 14 metres in length. In well "B", after drilling the channels, hydrochloric acid solution was injected through a special hydromonitor nozzle at two points. A total of 48 m3 of acid was injected into the "B" well.
Comparing the results of well "B" with the well where the hydrofracturing was performed allow speaking about high efficiency of the controlled radial drilling technology. The ability to predict the channel trajectory, knowledge of its actual trajectory in combination with acid treatment of the reservoir using hydromonitor nozzle at a considerable distance from the reservoir allows achieving a significant increase in oil flow rate with lower water cut of the produced oil.
99-110
Efficiency of horizontal wells in fields with highly viscous oil on the example of Tengri field
Abstract
Due to the growing share of high-viscosity oils in Kazakhstan, task of their effective development is becoming more complicated. Development of terrigenous reservoirs that have a complex structure and contain high-viscosity oil lead to low rates of sampling and low values of oil recovery factor. Currently, technologies that ensure high efficiency in development of such deposits are very expensive. The paper considers a pilot section of the development horizon of cretaceous system of the Tengri field, drilled with vertical wells in accordance with current project document. Further the average characteristics of the parameters of horizontal wells are compared and measures are proposed to improve the efficiency of further operation of these wells.
111-123