EAGE and SPE Joint Workshop: Geoscience Monitoring of the Field Development Process

Druzhnoe oil field was discovered in 1983. Main productive formation is Lower Cretaceous (beds BS10-11). Development started in 1985. In 2012 it became necessary to update entire geological model in the light of new 3D seismic data and petrophysical studies. In addition, existing model had poor predictive capabilities of reservoir properties. As part of model updating, a structural framework was corrected using all available seismic data and sub-vertical wells, more than 1000 well logs were re-interpreted. To match the same datum 3D seismic surveys misties were optimized with constant shifts; first derivatives calculated along the seismic lines were used for 2D surveys. In order to determine the reservoir genesis and its effect on porosity and permeability electric facies analysis and lithofacies mapping were made, estimated their correlation with the reservoir properties. New petrophysical models were built, permeability calculated using FZI, critical water saturation (at water-oil contact) determined from relative permeability data at 95% watercut, J-function used for correct presentation of water-oil transition zone. Finally, a 3D geological model was completely rebuilt, original oil in place evaluated.

Микросейсмический мониторинг является основным методом определения параметров трещин, образующихся при гидроразрыва пласта. В настоящее время существует два основных типа систем наблюдений при проведении микросейсмического мониторинга: наземная и скважинная. В первом случае приемники располагаются на поверхности над исследуемой областью, во втором - в вертикальных скважинах вблизи этой области. Исследование обратной кинематической задачи для анизотропных моделей позволяет решить ряд важных задач при обработке данных микросейсмического мониторинга. Можно одновременно производить локацию микросейсмических событий и уточнять параметры скоростной модели. При этом использование микросейсмических событий позволяет улучшать «освещенность» среды и оценивать анизотропные параметры. Можно также проводить количественную оценку точности локации и определения скоростей для конкретных систем наблюдений.

Development of new optical scanning instrument provided continuous high-precision measurements of thermal conductivity, volumetric heat capacity, anisotropy coefficient and rock heterogeneity factor on full-size cores. Continuous scanning of full-size cores gives profiles of thermal properties along the depth of the well. These data characterizes the reservoir heterogeneity at different scales and necessary for reservoir simulations. Obtained thermal property profiles are further used to select the core plugs for petrophysical measurements at bench and reservoir conditions. The approach was used to study more than 1000 core samples from 4 oil fields. Another new instrument for high-precision numerous measurements of the thermal properties on core plugs was developed. The thermal property measurements on core plugs were performed before and after core extraction, drying and saturation that provided monitoring of physical property and core condition variations on more than 300 samples. Developed experimental basis extended the area of application of thermal properties.

Monitoring by elecrtoprospecting methods - it’s studying of geoelectrical section parameters in time. Basing on previous years successful practice in monitoring on the South of Siberian platform, was estimated effectiveness of monitoring by TEM method on the North-Eastern part of East-European platform in a good-conductivity section conditions. In results of mathematical 1D modeling of electromagnetic signal for Timano-Pechorskaya oil-and-gas province geological conditions were shown, that TEM method is characterized by high sensitivity of geoelectrical parameters of target horizon changing after thermal-steam formation treatment. In results of 3D modeling nomogram was shown high sensitivity of transient signal from resistivity and reservoir volume, saturated by water vaporize. Application of monitoring by TEM method on high-viscosity oil deposits in big volume of steam injection could allow to retrace fluid migration pathways to reservoir bed.

The research is aimed to apply an integrated analysis of core and well logs for a subsequent rock physics modeling to do reservoir characterization using up-to-date seismic inversion technologies. The work outlines methodology and examples of seismic-to-well tie and reservoir forecast of unconventional formations and plays by means of seismic inversions. The results of using advanced methods for formation evaluation and reservoir characterization of unconventional shale plays, anisotropic thin-bedded reservoirs and other challenging cases are demonstrated

The horizontal well and hydraulic fracture stimulations, used to increase the productivity of Western Siberian oil fields, are very similar to the methods used to develop Shale Gas and Shale Oil reservoirs in other parts of the world. Recent microseismic mapping has revealed complications to those well completions that are similar to the complications experienced in unconventional reservoirs in other parts of the world.

Local Russian operators have been able to quickly adjust their well designs to negate those detrimental complications, by applying the lessons learned by other operators, from years of hydraulic fracture mapping in shale reservoirs. The microseismic acquisition techniques that are used will be described, including explanations of the specific local technical challenges that are overcome