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Levanyuk, Olesya (Schlumberger) | Overin, Alexander (Schlumberger) | Sadykov, Almaz (Schlumberger) | Parkhonyuk, Sergey (Schlumberger) | Lungwitz, Bernhard (Schlumberger) | Enkababian, Philippe (Schlumberger) | Klimov, Alexander (Imperial Energy) | Energy, Imperial (Imperial Energy) | Legeza, Sergey (Imperial Energy)
Abstract Scale deposits are a common problem in oil and gas wells and can have detrimental effects on well production. Depending on the severity, scaling can stop production entirely as scale forms anywhere in the well production system, including the formation, perforations, casing or tubular, and in or on the artificial lift equipment. There are several chemical and mechanical methods for removing scale deposits. However, to prevent scale deposition, the only solution is chemical inhibitors injected into the formation. The typical production system includes artificially lifted, stimulated wells (propped hydraulic fractures) placed in reservoirs where pressure maintenance is achieved by water flooding. The artificial lifting is typically accomplished through use of electric submersible pumps (ESPs). In reservoirs where produced fluids exhibit scaling tendencies, ESP run life is significantly shortened by scale formation on the pump elements restricting rotation. By treating the formation with chemical inhibitors, the life of the ESP can be extended. In this paper we provide approaches for improving a compatibility of a novel hydraulic fracturing fluid (used in Russia) and scale inhibitor. A 3-year campaign to combine scale inhibition with the hydraulic propped fracture effectively increased the average run life of ESPs in the Mayskoe and Snezhnoe oil fields.
Development of reservoirs of J14-16 tymen suite Mayskoe field was started in 2007, in operation 14 wells now are localized in two group of them in north and middle parts of fields. In the middle part was realized five-spot pattern with distance between wells 566 and 299 meters in different patterns (picture 1). In the north part well operation is doing without pressure maintenance. According to extremely low permeability (average for layers - low than 1 mD, maximum 4.7 mD) - all production wells were input in production after hydraulic fracturing jobs, some wells were fraced several times. Volume of proppant pumped into each fracture is in the range 40 - 150 ton. High volume fracs were done in 70% of wells. Liquid rates after hydraulic fracture was in the range 17 - 79 m3/day, with exponential decline (70% from initial at second month, just more 50% at third and stabilization after six month of production over the range 30 - 40% from initial) - picture 2. Current liquid rate of wells is in the range from 5.5 till 25.3 m3/day, watercut from 24 till 78%. Embodied supporting system was founded not effective. On the grounds of it by Schlumberger company were done project for enhance oil production from tumen suite reservoirs.
Abstract This paper describes a comprehensive analysis of the 3D seismic data, well logs, and cores from productive intervals of the Mayskoye and Festivalnoye fields. The analysis covered the sandstone layers of the lower part of Tyumen Formation and the fractured reservoirs of pre-Jurassic basement. The goal of this study was to build geological models that will serve as a basis for field development planning of the low-permeability, low-porosity reservoirs of the described intervals. First, we completed a structural and tectonic analysis, i.e. identified the main mechanisms of structural and tectonic evolution. At the Festivalnoye field, the main anticline structure is a pop-up fold that was formed by displacements along a major regional-scale wrench fault. This conclusion guided the structural interpretation, and in particular, resulted in more reliable fault recognition and tracing. The fault tracing widely involved the Ant Tracking function. The revealed direction of a regional stress (interpreted from FMI and sonic scanner data) has enabled a planning of the optimal trajectories for horizontal wells that is of special importance when hydraulic fracturing is involved. Second, we interpreted depositional environments and facies distribution of the Jurassic sandstone layers. In the Mayskoye productive interval we have identified two major parts of the section corresponding to different depositional systems: The lower section (zones J15—J16) was deposited in a braided river depositional system that fills the pre-Jursassic erosional relief. This environment was identified using the results of sedimentological core descriptions. The upper section (zones J12—J14) was deposited in a meandering river depositional system, with depositional cycles (sequences) topped with coals. This part of the section demonstrates higher heterogeneity compared to the lower unit deposited in braided rivers. The results of facies analysis provided grounds for the selection of optimal algorithms for geological modeling and adequate honoring of the reservoir heterogeneity. The conclusion about facies and the evolution of fluvial sedimentation for the lower part of the Tyumen Formation is presented first time for the southeastern region of Western Siberia.