Proizvodne karakteristike frakturiranih bušotina i rizici od procesa frakturiranja u nekonvencionalnim ležištima nafte i plina

master's thesis

• Title: Proizvodne karakteristike frakturiranih bušotina i rizici od procesa frakturiranja u nekonvencionalnim ležištima nafte i plina : diplomski rad
• Title (english): Production characteristics of fractured wells and risks from the fracturing process in unconventional oil and gas reservoirs : master's thesis
• Author: Aleksandra Pejovski
• Mentor: Sonja Koščak Kolin (mentor)
• Committee member: Sonja Koščak Kolin (predsjednik povjerenstva)
• Committee member: Vladislav Brkić (član povjerenstva)
• Committee member: Borivoje Pašić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Mining, Geology and Petroleum Engineering; (Department of Petroleum and Gas Engineering and energy); Zagreb
• Defense date and country: 2024-09-30, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Mining, Petroleum and Geology Engineering; Petroleum Mining

Abstract

Karakteristike nekonvencionalnih ležišta očituju se prvenstveno u maloj šupljikavosti i slaboj propusnosti stijene, koja je u plinskim ležištima niža od 0,1 mD (0,1E-15 m2), dok se naftna ležišta kategoriziraju nekonvencionalnima ukoliko je propusnost niža od 1 mD (1E-15 m2). Ključni pokazatelj proizvodnih mogućnosti bušotina u ovim ležištima je protok do bušotine, koji osim o propusnosti i šupljikavosti, uglavnom ovisi i o efektivnoj debljini, početnom tlaku te o karakteristikama pornih kanala. Prognoziranje proizvodnje ugljikovodika iz ovakvih ležišta temelji se na proizvodnim modelima za pritjecanje fluida iz ležišta u bušotinu kroz vertikalnu pukotinu ili kroz horizontalnu bušotinu, koji se analogno primjenjuju na višestruko frakturirane horizontalne bušotine. Kod ovih tipova stimuliranih bušotina dolazi do različitih oblika protoka, kao što su rani i kasni radijalni, rani i kasni linearni, bilinearni i pseudo-radijalni protok za koja postoje rješenja za tlak u bušotini, temeljem kojih se mogu odrediti proizvodne karakteristike bušotine, odnosno softverski postaviti proizvodni modeli za prognoziranje proizvodnje. Uspješnost procesa hidrauličkog frakturiranja, kao precizne stimulacijske aktivnosti koja je ograničena na djelovanje fluida u iniciranju i napredovanju pukotine u ležišnoj stijeni, utječe na proizvodne mogućnosti bušotine, jer one ovise i o konačnoj visini i poluduljini pukotine. Stoga se u naftno-plinskom inženjerstvu posebna pažnja posvećuje motrenju napredovanja pukotine. Iako je porast interesa javnosti za frakturiranje u nekim državama rezultirao značajnim strahom i nerazumijevanjem onoga što se događa u podzemlju, svi podaci ukazuju da frakturiranje u adekvatno konstruiranim bušotinama nije prijetnja prodiranju pukotine u podzemne vode i da ostali rizici općenito nemaju značajniji utjecaj na onečišćenje okoliša.

Abstract (english)

The characteristics of unconventional reservoirs are manifested primarily in low porosity and low rock permeability, which in gas reservoirs is lower than 0.1 mD (0.1E-15 m2), while oil reservoirs are categorized as unconventional if the permeability is lower than 1 mD (1E- 15 m2). The key indicator of the production possibilities of wells in these reservoirs is the flow to the well, which, in addition to permeability and porosity, mainly depends on effective thickness, initial pressure and the characteristics of pore channels. Hydrocarbon production forecasting from such reservoirs is based on production models for the flow of fluid from the reservoir into the well through a vertical fracture or through a horizontal well, which are analogously applied to multiple fractured horizontal wells. With these types of stimulated wells, different forms of flow occur, such as early and late radial, early and late linear, bilinear and pseudo-radial flow, for which there are solutions for pressure in the well, based on which the production characteristics of the well can be determined, i.e. software set up production models for production forecasting. The success of the hydraulic fracturing process, as a precise stimulation activity that is limited to the action of the fluid in the initiation and progression of the fracture in the reservoir rock, affects the production possibilities of the well, because they also depend on the final height and half-length of the fracture. Therefore, in oil and gas engineering, special attention is paid to monitoring the progress of the fracture. Although the increase in public interest in fracturing in some countries has resulted in significant fear and misunderstanding of what is happening underground, all data indicate that fracturing in adequately constructed wells is not a threat to fracture penetration into groundwater and that other risks generally do not have a significant impact on environmental pollution.

• Keywords: hidrauličko frakturiranje; nekonvencionalna ležišta; proizvodni modeli
• Keywords (english): hydraulic fracturing; unconventional reservoirs; production models
• Language: croatian
• URN:NBN: urn:nbn:hr:169:206581
• Study programme: Title: Petroleum engineering; specializations in: Petroleum engineering, Energy production and supply, Environmental protection in petroleum engineering; Course: Petroleum engineering; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka naftnog rudarstva (magistar/magistra inženjer/inženjerka naftnog rudarstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2024-12-17 10:57:40