New approach of complex uncertainties analysis at the exploration stage of the field is considered not only for geological properties but also for reservoir engineering, including the uncertainty of type of hydrocarbons saturation. The method shown in the work is based on the probabilistic method of HIIP estimation which is followed by probabilistic reservoir engineering uncertainties assessment in production profiles calculation.

The article considers the secondary transformations of carbonate rocks of oil and gas complexes, which are of fundamental importance in the formation of reservoir properties. For the first time, a schematic diagram, illustrating the regularities of secondary processes in carbonate reservoirs and their relationship with the physico-chemical conditions of the stratosphere is proposed.

One of the most promising oil and gas areas of the Pechora Sea shelf is the Dolginsko-Papaninskaya structural zone. Commercial hydrocarbon content has been proved by exploration drilling for the Carboniferous – Lower Permian carbonate reservoirs at the southern part of the structural zone (Dolginskoye field). However huge oil and gas potential in this region may also be associated with the Ordovician - Lower Devonian complex. Gazprom Neft is conducting systematic exploration and research projects on the Pechora Sea shelf in order to clarify the geological and geophysical parameters of prospective objects. 3D seismic data provided for the three license blocks demonstrate erosion and hypergene transformation of the Lower Devonian carbonate rocks within the uplifts of the Dolginsko-Papaninskaya structural zone. This transformation is a result of the Middle Devonian restructuring. There are local structures where the Lower Devonian sediments are cut off and the regional Timan-Sargaevsky argillaceous seal rocks overlap the carbonate rocks of the Ovinparmian horizon (Lochkovian stage). Secondary transformation of Ovinparmian sediments (dolomitization, dissolution, fracturing etc.) provide formation of high capacity reservoirs. It is spoken in details about sedimentation models and diagenesis transformation of the Ovinparmian carbonate rocks. Hypergene zones are confidently traced according to the materials of seismic facies analysis. The estimated resource potential of the Lower Devonian prospective objects is comparable to the Carboniferous – Lower Permian carbonate complex. The data on probable analogous fields localized in the adjacent tectonic areas are presented in the paper.

The rocks of the Achimov deposits are known for low porosity, permeability and poor connectivity of the pores. They belong to the Lower Cretaceous complex and have a complex geological structure. Oil and gas-bearing objects in the Achimov deposits belong to the non-anticlinal type of traps and are confined to clinoforms. The question of studying the volume of mobile water in the rocks of the Achimov is important, but is still open. The success of geological exploration and the risks of production drilling depend on the effectiveness of solving this problem.

One of the important modern tasks in seismic is to increase the resolution of the wave field. In general, the resolution of the wave field estimates as 1/4 wavelengths. At this thickness, the separate interpretation of top and bottom become impossible. There are several algorithms designed to solve the problem of limiting the resolution. These algorithms can include the “whitening” of the frequency spectrum, as well as the use of inversion, which, by taking into account the signal shape, can reduce the influence of interference. In this study, we consider the use of sparse approximation to increase the resolution of the wave field. These algorithms are based on using a given dictionary of wavelets to describe the input seismic path. At the same time, the composition of the dictionary has a significant impact on the result. The article describes the process of forming a dictionary and testing it on model data in order to study the effectiveness of this method.

This article reveals the possibilities of applying the results of spectral inversion on the example of a field in Eastern Siberia and shows the advantages of this approach over standard methods.

The article proposes a method for normalizing neutron logging readings, considering the degree of carbonatization of rocks based on the use of lateral logging data. The presence of a large amount of carbonate cement leads to a decrease in the parameters of porosity and permeability, which cannot always be determined by standard methods for determining the reservoir properties by well logging. Recalculation of permeability, performed according to the proposed method, allows to consider the risks of low starting parameters in the areas affected by carbonatization.

The paper considers the reasons for the decrease in the efficiency of deflection technologies in the fields of Western Siberia and proposes implements for control the negative effect.

The paper reviews actual production results and production forecasting for horizontal wells completed using multistage hydraulic fracturing in Bazhenov formation of Palyan area, Krasnoleninskoye oilfield (HMAO). The key feature of these reservoirs is high degree of uncertainty in geological and geomechanical properties. The primary purpose of this study is to provide both identification of correlation between well productivity index (rates, cumulative production) and general geological-technological factors and software development for production forecasting of Bazhen formation wells. In the course of the works, more than 2000 probable correlations between geological and geomechanical formation properties as well as between technological factors and well performance have been analyzed. Main key complex parameters (length of horizontal section, number of frac stages, average tonnage of proppant and fracturing fluid back-production) that govern producing well performance have been determined in this analysis. The approach for evaluation of forecast well performance (initial rate, cumulative oil production) is provided on the basis of obtained statistical correlations and machine learning techniques. Approaches described in this paper summarize the first results of the phase «Select» in progress of pilot project on Palyan area, Krasnoleninskoye oilfield.

The article describes new decline curves (DC) forecasting method for project wells. The method is based on the integration of manual grouping of DC and machine learning (ML) algorithms appliance. ML allows finding hidden connections between features and the output. Article includes the decline curves analysis of two well completion types: horizontal and slanted wells, which illustrates that horizontal wells are more effective than slanted.

This paper describes an approach to creating a virtual flow metering system (VFM). Proposed method is based on electric submersible pump system’s monitoring. Whole VFM market was analyzed with taking method’s relevance, possible and real industry applications into consideration. Created algorithm uses data that is regularly collected from oilfields and stored in corporate’s databases. Mainly used parameters are well’s construction, telemetry data from ESP system, pressure and temperature from different parts of the well, and available oil production data, divided by phases, that is obtained rarely and used for calibration. Suggested solution considers electric part of an ESP system and so it reveals possibility to estimate ESP degradation dynamics for liquid-gas mixture production restoring by using correction coefficients. Presented algorithm was tested on the Company’s oilfield. One well is shown as an example of method’s work, including all steps from data preprocessing to liquid production dynamics recovering. Also results of algorithm usage on several dozen wells on various oilfields are presented. As one of the main results approving the possibility to increase liquid production measurements frequency should be mentioned. Such possibility is based on using indirect operating parameters and recovering dynamics of model’s inner coefficients (e.g., ESP degradation), that make possible to estimate effectiveness of pump exploitation and possible optimization necessity. As another important result implementing of the algorithm into Company’s IT systems should be mentioned. Such implementation reveals possibility for monitoring a big amount of wells in fast and effective way

An information system is proposed that uses a new complex methodology for choosing a method for well operation based on applicability criteria and boundary conditions for the parameters of mechanized productivity technologies. A mechanism for selecting technologies is presented, which consists of filtering the general register of technologies according to the selected parameters for assessing the total cost of ownership at the Company’s fields. The process of forming and updating the technology base, criteria of applicability and their boundary conditions is considered. Graphic materials illustrate the prototype of this system. The developed methodology will speed up the process of introducing new production technologies, which in turn will lead to a positive economic effect – a decrease in the total cost of ownership of equipment for oil production at the Exploration and Production Block.

The geology of oilfields is becoming more complex, which leads to uncertain distribution of petrophysical properties. Quality of reservoir properties prediction depends on petrophysical models and log interpretation algorithms. It is also connected with the level of expertise of each petrophysicist as well as knowledge sharing among experts and young specialists. The aim of this paper is to present Gazprom Neft Science and Technical Centre approach to development of petrophysical competences with communities of practice.