Today, Tatneft PJSC is intensively studying and developing production technologies for Domanic formations in Tatarstan. Over the last 3-5 years, the USA companies have made significant progress in shale reservoir development, which required billions of dollars and over 20 years of research. The USA companies’ experience could be used in Tatarstan to reduce financial and time expenditures. However, these technologies must be customized for Tatarstan fields, with due regard for their special features.
This paper discusses technologies used for shale reservoir studies and development in the USA. The standard suite of core, cuttings and fluid analyses includes application of X-ray diffraction (XRD) equipment, kerogen examination, use of spectrometer and electronic scanning microscope, thin-section petrography, isotope and chromatographic analyses (RCA), proppant and fracturing agent tests, determination of capillary pressure, and rock mechanics survey. In addition, some special or supplementary survey can also be carried out. Domanic reservoirs in Tatarstan are similar to Shaly Carbonate reservoirs that are successfully produced in the USA. The initial production of oil from wells with a horizontal section 1,600-3,200 m long is 130-200 t/d after 20-40-stage fracturing. Major portion of oil is produced during the first year and a half, which is followed by pressure depletion and production decline. 2.5-3 years later, multi-stage fracturing is conducted again, and this increases well economic life by 2-2.5 years. Payback period for 4 mln dollars CAPEX (240 mln RUB) is 6-12 months. To achieve such results in the Domanic formations, extensive R&D efforts are required. Based on the numerical simulation, more fracturing stages and longer horizontal wells produce better results.
The paper reviews innovative technologies and procedures based on machine learning, which enable having total high-resolution data set without expensive geophysical surveys and analyses of large amount of core and cuttings samples. Such technologies and procedures allow defining drilling location, interval and direction of horizontal drilling, placement of perforation clusters and frac stages, as well as multi-stage fracturing design and fracture growth monitoring.
References
1. URL: https://www.eia.gov/maps/images/shale_gas_lower48.jpg
2. Khisamov R.S., Akhmetgareev V.V., Khakimov S.S., Kenzhekhanov Sh.Sh., Technology of multistage hydraulic fracturing in horizontal wells: Development experience of Shaly carbonates in the US and Its adaptation for the fields of the Republic of Tatarstan (In Russ.), Georesursy = Georesourses, 2017, V. 19, no. 3, pp. 186–190.
