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Summary Integrated asset development project planning is based on delivering maximum effectiveness of hydrocarbon reserves development, formulating the concept of optimum development and operation of the asset in the long run. The fundamental of integrated asset development project planning is formation of integrated well intervention programs (hereinafter referred to as the well intervention) – commissioning of new wells, frac, side-tracking on the operating well stock, recompletion, etc. Relevance of well intervention planning process is evident – oil, water and gas production capacity and water injection are calculated based on the worked out well intervention programs, infrastructure development and construction is designed, and project efficiency is evaluated. The authors describe the process of formation of integrated well intervention programs, using digital information systems at the Priobskoye field (southern concession area). Remaining recoverable reserves of the field constitute 362 mn t of oil, the operating well stock of the field exceeds 2,000 wells, more than 500 well interventions are carried out annually. In 2015, a digital information system – IS Well Intervention Selection (algorithms are described in SPE- 176561) – was put in commercial operation; the engineers use this system to make calculations for selecting well intervention – frac and side-tracking, and align well interventions. The system is based on a web interface enabling vizualization of results, prompt computations and decision-making for all related specialists in the real time mode, while accumulating and saving the history. Technical support procedure is established; the interface is periodically upgraded in connection with functionality enhancement. Within 2015, the number of completed repeated frac activities has been increased to 180 operations p.a. (+50 wells) with startup increase to 14 tpd (+2 tpd), 76 tons of oil have been produced over the target. In 2016, according to the expert assessment of the activities potential, it is planned to increase the number of repeated frac activities to 260 operations per year (+100 wells to the business plan). In 2016, a new digital information system project – "New Well Drilling Rating" is to be launched. The project guideline has been elaborated, and the new well drilling rating template has been implemented. The system functionality for each new planned well by strata includes a block of geological and process information, computation modules for expert and probabilistic assessment of flowrates, reserves, production capacity with probability 10%, 50% and 90% (hereinafter referred to as P-10, P-50, P-90), a module of the financial economic model for estimation of all development scenarios.

With each year drilling of new wells is performed in worse and worse reservoir properties conditioned by low permeability and undersaturated reservoir. At the same time, percentage of hi-tech horizontal wells (HW) with multistage hydraulic fracturing (MSHF) is increased, advanced technologies and engineering solutions are deployed; all this allows to maintain and even increase levels of oil production in new wells. As at beginning of 2017, over 200 MSHF HWs have been drilled in the unique Priobskoe field (South Concession Area) with use of the most advanced technologies. Various completion types and MSHF technologies have been deployed and tried in 50 areas in search of the best technologies and engineering solutions. Wells in such areas were producing for more than 1year and at this stage there is adequate amount of data on cumulative production, liquid and oil decline rates for efficiency benchmarking. Number of commissioned MSHF HWs is increased each year and there will be over 600 MSHF HWs by 2019 (+300% to current number) and results of this paper is a determining vector of development for further decisions applicable to improvement of efficiency of MSHF horizontal wells. The following main points for increasing efficiency of MSHF HWs were identified by results of the benchmarking: Increase of HW length to max. 1500 m allows to increase productivity, obtain incremental cumulative production over 20% vs. offset wells with HW length ~ 1000 m.Depending on the distance between ports, an optimal number of MSHF stages is ~ 125 m; in some cases, this distance is increased to ~150 m for large volumes of proppant > 90 tons per stage.Increased mass of proppant > 90 tons per stage (maximum 122 tons, up to 10 tons per 1 meter of formation) allowed to obtain incremental cumulative production from 20 to 48% during the first year as compared to offset wells with proppant mass <50 tons per stage.An optimal range of proppant mass identified for the undersaturated reservoir is 50-60 tons per stage depending on the TVDSS. Success of cluster MSHF was reported for some wells.Use of internal-flush cemented liners with targeted initiation of fractures shows good results in some areas. Subject to the quality cementing, this is the most strategically promising and anticipated approach for the repeated targeted MSHF. History of decline rates, operational experience of fraced directional wells show that over 200 re-MSHFs shall be performed in the next 10 years.

The active building of HW with MSHF use for ensuring their effective development in low-permeability reservoirs, but there are certain difficulties with getting completely information for making the right decisions during control of development. As part of the work performed, the main uncertainties and the further application of research results for estimates the profile of horizontal well (HW) with multi-stage hydraulic fracturing (MSHF) for planning the necessary geological and technical actions based on more than 20 operations at the South Priobskoye field are shown. The following field geophysical tests were executed in wells: PLT with Y-tool and CT + spectral noise logging module;PLT during compression with CT + multi-sensor flow meter;PLT with a well tractor;tracer studies (proppant, frac sleeves);thermometry with using fiber-optic system in injection and production wells.

Horizontal multi-fractured wells nowadays are the most common way of low-permeability reservoirs exploitation either in Russian and foreign oilfields. Besides its high efficiency such completion has a lot of factors (usually undefined) which can together significantly decrease oil rate. Here some of them are listed: Drilled horizontal well length and producing well lengthNumber of created and producing fracturesFracture length by design and by the actual production and well-testFracture location in relation to well (azimuth and initialization interval).Interference between neighborhood wells through the fractures during injection and productionEtc. The paper deals with most interesting parts of a complex project which purpose is to realize the multi-fractured well potential and production system diagnostics. There are three main issues in this paper: Designing – filed-sector choosing, optimum spacing and well completion calculations Realization – well construction and studies conduction Analysis – comparison between new project wells and common wells in the neighborhood, geological and hydrodynamic model correction Current primary project result is a significant exploitation system efficiency growth after a change of well and fracture directions (perpendicular to the wellbore). The secondary but anyway very important results are learned lessons and new competences in well construction and studies.