The course aims at providing the knowledge needed to investigate and characterize hydrocarbon reservoirs through well measurements. Specific goals of the course are to provide the ability to perform the analysis, quality check and interpretation of static measurements recorded via well logging for determining the hydrocarbon volume initially in place and of dynamic measurements recorded via well testing for assessing the production potential of the system. To this end the course will focus on the equipment available for data gathering, testing procedures, uncertainties associated to well measurements, interpretation models, pressure transient analysis and their applicability and/or limitations. The skills gained in the course will allow the students to acquire the competences needed to efficiently communicate with experts from other disciplines who can provide scientific and technical insights or design constraints for an effective reservoir characterization. Attitude to an accurate and meticulous approach to data analysis and management is an essential trait of this course.

Students will acquire: - Deep knowledge of the technologies and methodologies applied for the characterization of hydrocarbon-bearing formations through geophysical logs as well as through the analysis of pressure transients (well tests). - Ability to handle the methods and software adopted worldwide in the oil industry for static and dynamic reservoir characterization based on a good understanding the principles and assumptions they rely upon. - Ability to unlock the key technical information from data, graphs, and other convenient tools or representations. - Ability to capture the essential messages, the methodologies and their implications from technical papers and manuals.

Students should have a good knowledge of geophysics, geology, fluid mechanics and reservoir engineering to be able to truly understand well measurements, which are the basis for reservoir rock characterization and estimation of the hydrocarbon in place and for describing the reservoir dynamic behavior and production performance. It is essential that students master the concepts and the basics of rock and fluid properties and their mutual interactions, the flow equations, and the pressure analysis and interpretation techniques. Familiarity with the orders of magnitude of the most relevant quantities (fluid properties, petrophysical characteristics, fluid-rock interaction properties, recovery mechanisms) is required.

- Introduction to well logging - Geophysical log technologies: measurements, correlations and corrections: > Lithological logs – self potential and gamma ray > Resistivity logs > Radioactivity logs – neutron and density logs > Sonic logs > Other logs – image logs, NMR - Log interpretation – formation evaluation: > Zonation and lithology recognition (clay index) > Use of neutron – density crossplot > Porosity, net to gross and water saturation estimation > Log inversion - Introduction to well testing - Equipment, data collection, and QC - Types of well testing (DST, Production test, Limit test, Interference tests) - Gas and oil equations for well production from a closed reservoir - Build-up equation and Horner plot - Introduction to pressure derivatives - Well tests interpretation with pressure derivatives: > Early time models > Middle time models > Late time models > Interference tests - Unconventional well testing (mini-DST, injection testing, harmonic testing)

Some of the theoretical lessons will be held with the collaboration of highly qualified technical staff from oil and/or service companies, who will give lectures on applications to real cases.

Exercises will include application of the methodologies presented and discussed during lectures to case studies based on synthetic and real data, with increasing degree of complexity. The software commonly adopted in the oil industry for log analysis and well test analysis will be used. Under the guidance of the professor, students will be encouraged to work independently.

Bourdet D., 2002. Well test analysis: the use of advanced interpretation models. Elsevier. Horne R., 2001. Computed aided well test analysis, Stanford University, Petroway Inc. Technical Papers will be provided (unlimited free download from the SPE One-Petro library is also available) The slides presented during lectures will be periodically posted on the course website

Modalità di esame: Prova scritta (in aula); Prova orale obbligatoria;

Exam: Written test; Compulsory oral exam;

... The exam is subdivided in two sections, one for Well Logging part and one for Well Testing part, both aimed at evaluating knowledge, competences and skills acquired during the course. The capability to integrate knowledge gained in other courses and contexts, to critically examine a technical problem and to select models and methods to reach the solution is expected. Well logging part The examination will be written and will consist in at least three questions concerning: • description of log tools technologies, physical principles of the measurements, derived parameters and interpretation, required corrections and uncertainties; • exercise on petrophysical parameters characterization; • quantitative interpretation of a set of well log measurements for a given formation interval. Well testing part The examination will consist in two parts. • A presentation (20 minutes) and open discussion (10 minutes) of a technical paper selected out of a list of papers on new and/or unconventional well tests provided by professors. A power point presentation is expected for the presentation; failure to submit the presentation within the assigned deadline implies the student will not be allowed to take the exam on the next exam date. • A written test concerned with the theoretical parts, description of conventional and unconventional well test methodologies, interpretation models, well test design and problem solving. The test is closed-books.

Gli studenti e le studentesse con disabilità o con Disturbi Specifici di Apprendimento (DSA), oltre alla segnalazione tramite procedura informatizzata, sono invitati a comunicare anche direttamente al/la docente titolare dell'insegnamento, con un preavviso non inferiore ad una settimana dall'avvio della sessione d'esame, gli strumenti compensativi concordati con l'Unità Special Needs, al fine di permettere al/la docente la declinazione più idonea in riferimento alla specifica tipologia di esame.

Modalità di esame: Prova orale obbligatoria;

The exam is subdivided in two sections, one for Well Logging part and one for Well Testing part, both aimed at evaluating knowledge, competences and skills acquired during the course. The capability to integrate knowledge gained in other courses and contexts, to critically examine a technical problem and to select models and methods to reach the solution is expected. Well logging part The examination will be oral and will consist in at least three questions concerning: • description of log tools technologies, physical principles of the measurements, derived parameters and interpretation, required corrections and uncertainties; • exercise on petrophysical parameters characterization; • quantitative interpretation of a set of well log measurements for a given formation interval. Well testing part The examination will consist in two parts: • A presentation (20 minutes) and discussion (10 minutes) of a technical paper selected out of a list of papers on new and/or unconventional well tests provided by professors. A power point presentation is expected for the presentation. failure to submit the presentation within the assigned deadline implies the student will not be allowed to take the exam on the next exam date. • An oral interview concerned with the theoretical parts, description of conventional and unconventional well test methodologies, interpretation models, well test design and problem solving. . Both the oral examinations will be through BBB or Zoom platform. The final mark will be calculated as an average of the results obtained for each exam section. Rules during online oral exams: students must show their identification document and this will be compared with the student’s photo available in the database of the University; a witness (who is not a member of the Board of Examiners) will be present during the exam; students must declare that they are not using any aid or support tool and that nobody is in the room to help them during the exam. Student must be alone in the room, on a table clean from papers/pad /phone or whatever else than pocket calculator, white papers, and a pen. The student might be asked to share the screen during questions. If the connection is lost, the exam will have to be restarted from the beginning. It is decision of the professor to offer opportunities for redoing the exam in case of technical problems.

Modalità di esame: Prova orale obbligatoria;

The exam is subdivided in two sections, one for Well Logging part and one for Well Testing part, both aimed at evaluating knowledge, competences and skills acquired during the course. The capability to integrate knowledge gained in other courses and contexts, to critically examine a technical problem and to select models and methods to reach the solution is expected. Well logging part The examination will be oral and will consist in at least three questions concerning: • description of log tools technologies, physical principles of the measurements, derived parameters and interpretation, required corrections and uncertainties; • exercise on petrophysical parameters characterization; • quantitative interpretation of a set of well log measurements for a given formation interval. Well testing part The examination will consist in two parts: • A presentation (20 minutes) and discussion (10 minutes) of a technical paper selected out of a list of papers on new and/or unconventional well tests provided by professors. A power point presentation is expected for the presentation. failure to submit the presentation within the assigned deadline implies the student will not be allowed to take the exam on the next exam date. • An oral interview concerned with the theoretical parts, description of conventional and unconventional well test methodologies, interpretation models, well test design and problem solving. . Both the oral examinations will be through BBB or Zoom platform. The final mark will be calculated as an average of the results obtained for each exam section. Rules during online oral exams: students must show their identification document and this will be compared with the student’s photo available in the database of the University; a witness (who is not a member of the Board of Examiners) will be present during the exam; students must declare that they are not using any aid or support tool and that nobody is in the room to help them during the exam. Student must be alone in the room, on a table clean from papers/pad /phone or whatever else than pocket calculator, white papers, and a pen. The student might be asked to share the screen during questions. If the connection is lost, the exam will have to be restarted from the beginning. It is decision of the professor to offer opportunities for redoing the exam in case of technical problems.