SLIM-TUBE SIMULATION MODEL FOR CO2 INJECTION EOR

Simulacijski model duge, uske cijevi (slim-tube) kreiran je u svrhu validacije eksperimenta i ugađanje jednadžbe stanja, a potencijalno i kao alat za brzo i pouzdano određivanje minimalnoga tlaka miješanja (MMP) uz uvjet da je razvijena jednadžba stanja za razmatranu naftu. Brojne analize osjetljivosti napravljene su mijenjanjem sastavnih varijabli simulacijskoga modela (broj ćelija, Correyjevi eksponenti krivulja relativnih propusnosti, promjena brzine utiskivanja te termodinamičkoga (PVT) modela). Minimalni tlak miješanja dobiven simulacijom određen je kao sjecište dviju različitih krivulja u funkciji utisnoga tlaka i kumulativnoga iscrpka pri svakome tlačnom koraku. Vidljivo je da u pogledu određivanja minimalnoga tlaka miješanja postoji dobra podudarnost s laboratorijskim podatcima, no uz nešto podcijenjen konačni iscrpak nafte u osnovnome testiranom modelu. Moguće je izdvojiti „X-tip” relativnih propusnosti kao potencijalni izvor odstupanja koje su u modelu korištene istovjetno, pri svim tlačnim koracima (za nemješive te djelomično i potpuno mješive uvjete). Konačno, finim ugađanjem binarnih interakcijskih parametara u simulacijskome modelu te promjenom relativnih propusnosti za nemješive uvjete moguće je postići vrlo dobro slaganje s eksperimentalnim podatcima.A simulation model of the slim-tube test has been developed to validate the laboratory experiment and used EOS as well as to investigate the possibility of serving as a fast and reliable tool for MMP determination. Sensitivity analyses were performed by testing different grid block sizes (different number of cells), changing Corey’s coefficients for relative permeability curves, varying flow rates and PVT models. Minimum miscibility pressure from the simulation model is estimated as the intersection of the two different trend line curves of oil recoveries versus the injected volume of CO2. The oil recoveries were underestimated by numerical simulation on a basic case model. This is related to the usage of single “X shaped” relative permeability curves in all simulation cases, i.e. for immiscible, near miscible and miscible conditions. In addition, by fine tuning binary interaction parameters in equation of state model and introducing different relative permeability curves for immiscible and near miscible cases, better matching of slim-tube simulation can be achieved

Određivanje rasporeda veličine pora uz pretpostavku različitih pornih geometrija

Opisane su metode mjerenja kapilarnih tlakova te fizikalna povezanost kapilarnih tlakova, tj. močivosti i geometrije pora. Predstavljeni su različiti geometrijski modeli kojima se može predstaviti porni prostor uzorka stijene te su izračunate i uspoređene raspodjele veličina pora uz različite pretpostavke njihove geometrije. Ustanovljeno je kako pri najmanjim radijusima pora, odabir geometrije ne utječe bitno na procjenu njihove zastupljenosti, međutim kod većih pora pretpostavka geometrije pora može bitno promijeniti procjenu raspodjele veličina pora. Korištene su dvije različite metode računanja: metoda temeljena na procjenama radijusa zakrivljenosti meniskusa u kapilari i MSP-OBA metoda koja koristi omjer površine pora i njihovog opsega. Kako se zakrivljenost pore približava obliku kružnica, raspodjela će davati sve veće vrijednosti ekvivalentnog polumjera pora zbog smanjenja utjecaja zaostajanja močive faze u kutevima pora. Naposljetku, napravljena je i statistička analiza raspodjele veličine pora

Quality Management: Patients Reflections on Health Care at Outpatient Clinic of Internal Medicine Department

Middle and older age group relative share in the community permanently grows. Those are commonly burdened with several chronic health conditions or elevated incidence of acute ones and in more frequent need for consulting health services. In the era of modern technical medicine, it is important to increase quality of services particularly patients orientated. Department of Internal medicine developed questionnaire to assess reflections on medical care from the receiver of medical services point of view. Sample was formed from individuals that visited outpatient triage Unit (OTU) and voluntary enrolled, during period April 1 – August 31 2008 for any medical reason. Study population structure had similarly equally of both genders, socio-economical background, and was in age range 18–87. Questionnaire was developed by team of experienced personnel covering satisfaction on received medical care. There were 279 returned formulary in a sample of 6700 patients (4.18%). Patients visited OTU chiefly on behalf medical condition secondary to address of residency, followed by personal choice, on advice given by general practitioner, by emergency transportation services, or just due to earlier experiences. Regarding provided medical care extent, 4/5 of patients were examined in lesser than 2 hours, while total workup lasted mostly for 2–4, followed by over four. Over half of patients were moderate toward highly satisfied with provided medical information, personnel communication style and general reflection on all services while being in the Department premises. Astonishing proportion of patients (93%) was satisfied with positive personnel communication. Integration of patients’ self-perceived reports about medical services in organizing process is inevitable for augmenting content and at the same time valuable for developing overall quality of treatment. Communication excellence is of premier importance and unavoidable for giving additional positive effect to remain health status or to ease the healing process of individual and their families

Position of Intragastric Balloons in Global Initiative for Obesity Treatment

Obesity is chronic disease with multiple health consequences and among the most severe health problems worldwide. According to public health records around 65% of population in Croatia are overweight and 20% obese. National physicians chamber with support of Health and Social Welfare Ministry gave recommendations on diagnosing and treating of obesity in form of national consensus. Treatment of obesity is complex and enrolls multiple clinical specialties. Change of life style, strenuous physical activity and pharmacotherapy are part of conservative treatments. Patients are treated more efficiently by minimally invasive endoscopic procedures or bariatric surgery depending on starting body mass index score. Implantation of intragastric balloons is conceptually simple method of obesity treatment. Modern devices as Bio- Enterics intragastric balloons (BIB®), (Inamed Health, USA) are gaining wide popularity among both patients and physicians. BIB intragastric offers the best gains with individuals ranging BMI from 35 to 40. Efficiency has relative timeline dependance from 85% at 6 months to 24% at 36 months. BIB offers substantial ameliorative influence on obesity comorbidities, particularly cardiovascular risk. Treatment with BIB is also efficient but transient treatment modality in morbidly and superobese individuals to reduce preoperative risks of general and bariatric surgery. Obesity treatment with BIB is well tolerated and safe, offering better quality of life. Nevertheless, due to relative poor results of conservative obesity treatments on long term follow up further investigations defining new clinical parameters for solving treatment resistance. In order to provide resourcefully individualized approach modern perspectives are focused on endocrine constitutes of obesity. Hormonal effects of BIB treatment in compare to bariatric surgery are potentially interesting for the prospect studies

Development of a new neutron probe for borehole research

Neutronska proba za ispitivanje naftnih bušotina razvijena je na Institutu Ruđer Bošković u okviru HRZZ projekta IP-2018-01-4060 \u27\u27Nove primjene 14 MeV neutrona\u27\u27. U ovom istraživanju ispitane su daljnje mogućnosti redukcije šuma u mjerenju C/O omjera metodom pridružene alfa čestice. Mješavina kvarcnog pijeska i grafitnog praha korištena je kao materijal od interesa , dok su plastične bočice ispunjene dizel gorivom korištene kao šum (smetnja) i predstavljaju tekućinu unutar naftne bušotine (npr. nafta). Podjela alfa detektora na četiri jednaka segmenta, omogućila je podjelu volumena oko osi neutronske probe na četiri kvadranta. Materijal od interesa i dizel smješteni su u različite kvadrante i pokazano je da su C/O vrijednosti u slučajevima kad je smetnja prisutna unutar statističke greške u odnosu na slučaj kada smetnje nema.The neutron probe for testing oil wells was developed at the Ruđer Bošković Institute within the HRZZ project IP-2018-01-4060 "New applications of 14 MeV neutrons". In this study, further possibilities of noise reduction in C/O ratio measurement by the associated alpha particle method were investigated. A mixture of quartz sand and graphite powder was used as the material of interest, while plastic bottles filled with diesel fuel were used as noise (interference) and represent the liquid inside the oil well (e.g. oil). Dividing the alpha detector into four equal segments, allowed portioning the volume around the neutron probe axis into four quadrants. The material of interest and diesel were located in different quadrants and it is shown that the C/O values in cases where interference is present are within statistical errors compared to the case where there is no interference

Creating pVT properties correlations for oil samples from the Sava and Drava depressions : master's thesis

Korištenjem pVT simulatora Schlumberger Eclipse napravljena je simulacija pVT analize prema podacima prikupljenim s naftnog polja Žutica. U sklopu simulacije izvršeni su testovi diferencijalnog otparavanja (DL), ekspanzije fluida uz konstantni sastav (CCE) te test tlaka zasićenja s ciljem dobivanja vrijednosti volumnog faktora nafte Bo, faktora otopljenog plina Rs i relativnih gustoća nafte i plina, kao funkcije tlaka pri konstantnoj temperaturi. Korelacije koje su pokazale najmanju relativnu pogrešku u odnosu na rezultate dobivene simulacijom su podvrgnute korekciji korelacijskih konstanti numeričkim modeliranjem. Time se maksimalno približilo vrijednostima pVT simulacije te je relativna pogreška tako dobivene korelacije bila najmanja.Abstract Using the Schlumberger Eclipse pVT simulation software, a pVT analysis was made on data series from Žutica oilfield. In terms of pVT simulation, Differential Liberation, Constant Composition Expansion and Saturation Pressure tests are performed in order to develop the Formation Volume Factor, the Solution Gas Factor, and oil and gas gravity values, all as functions of pressure within constant temperature. Correlations with minimal relative error values are chosen for further development. Their correlation constants were altered to match pVT simulation values by numerical modeling. That way, correlations with new correlation constants had the lowest relative error values compared to pVT analysis data

Creating pVT properties correlations for oil samples from the Sava and Drava depressions : master's thesis

Korištenjem pVT simulatora Schlumberger Eclipse napravljena je simulacija pVT analize prema podacima prikupljenim s naftnog polja Žutica. U sklopu simulacije izvršeni su testovi diferencijalnog otparavanja (DL), ekspanzije fluida uz konstantni sastav (CCE) te test tlaka zasićenja s ciljem dobivanja vrijednosti volumnog faktora nafte Bo, faktora otopljenog plina Rs i relativnih gustoća nafte i plina, kao funkcije tlaka pri konstantnoj temperaturi. Korelacije koje su pokazale najmanju relativnu pogrešku u odnosu na rezultate dobivene simulacijom su podvrgnute korekciji korelacijskih konstanti numeričkim modeliranjem. Time se maksimalno približilo vrijednostima pVT simulacije te je relativna pogreška tako dobivene korelacije bila najmanja.Abstract Using the Schlumberger Eclipse pVT simulation software, a pVT analysis was made on data series from Žutica oilfield. In terms of pVT simulation, Differential Liberation, Constant Composition Expansion and Saturation Pressure tests are performed in order to develop the Formation Volume Factor, the Solution Gas Factor, and oil and gas gravity values, all as functions of pressure within constant temperature. Correlations with minimal relative error values are chosen for further development. Their correlation constants were altered to match pVT simulation values by numerical modeling. That way, correlations with new correlation constants had the lowest relative error values compared to pVT analysis data

Creating pVT properties correlations for oil samples from the Sava and Drava depressions : master's thesis

Korištenjem pVT simulatora Schlumberger Eclipse napravljena je simulacija pVT analize prema podacima prikupljenim s naftnog polja Žutica. U sklopu simulacije izvršeni su testovi diferencijalnog otparavanja (DL), ekspanzije fluida uz konstantni sastav (CCE) te test tlaka zasićenja s ciljem dobivanja vrijednosti volumnog faktora nafte Bo, faktora otopljenog plina Rs i relativnih gustoća nafte i plina, kao funkcije tlaka pri konstantnoj temperaturi. Korelacije koje su pokazale najmanju relativnu pogrešku u odnosu na rezultate dobivene simulacijom su podvrgnute korekciji korelacijskih konstanti numeričkim modeliranjem. Time se maksimalno približilo vrijednostima pVT simulacije te je relativna pogreška tako dobivene korelacije bila najmanja.Abstract Using the Schlumberger Eclipse pVT simulation software, a pVT analysis was made on data series from Žutica oilfield. In terms of pVT simulation, Differential Liberation, Constant Composition Expansion and Saturation Pressure tests are performed in order to develop the Formation Volume Factor, the Solution Gas Factor, and oil and gas gravity values, all as functions of pressure within constant temperature. Correlations with minimal relative error values are chosen for further development. Their correlation constants were altered to match pVT simulation values by numerical modeling. That way, correlations with new correlation constants had the lowest relative error values compared to pVT analysis data

Quality management: patients reflections on health care at outpatient clinic of internal medicine department [Upravljanje kvalitetom: mišljenja pacijenata o zdrastvenoj skrbi na odjelu prijemne ambulante Klinike za unutarnje bolesti]

Middle and older age group relative share in the community permanently grows. Those are commonly burdened with several chronic health conditions or elevated incidence of acute ones and in more frequent need for consulting health services. In the era of modern technical medicine, it is important to increase quality of services particularly patients orientated. Department of Internal Medicine developed questionnaire to assess reflections on medical care from the receiver of medical services point of view. Sample was formed from individuals that visited outpatient triage Unit (OTU) and voluntary enrolled, during period April 1-August 31, 2008 for any medical reason. Study population structure had similarly equally of both genders, socio-economical background, and was in age range 18-87. Questionnaire was developed by team of experienced personnel covering satisfaction on received medical care. There were 279 returned formulary in a sample of 6700 patients (4.18%). Patients visited OTU chiefly on behalf medical condition secondary to address of residency, followed by personal choice, on advice given by general practitioner, by emergency transportation services, or just due to earlier experiences. Regarding provided medical care extent, 4/5 of patients were examined in lesser than 2 hours, while total workup lasted mostly for 2-4, followed by over four. Over half of patients were moderate toward highly satisfied with provided medical information, personnel communication style and general reflection on all services while being in the Department premises. Astonishing proportion of patients (93%) was satisfied with positive personnel communication. Integration of patients' self-perceived reports about medical services in organizing process is inevitable for augmenting content and at the same time valuable for developing overall quality of treatment. Communication excellence is of premier importance and unavoidable for giving additional positive effect to remain health status or to ease the healing process of individual and their families

Position of intragastric balloons in global initiative for obesity treatment [Pozicija intragastričnih balona u globalnoj inicijativi liječenja pretilosti]

Obesity is chronic disease with multiple health consequences and among the most severe health problems worldwide. According to public health records around 65% of population in Croatia are overweight and 20% obese. National physicians chamber with support of Health and Social Welfare Ministry gave recommendations on diagnosing and treating of obesity in form of national consensus. Treatment of obesity is complex and enrolls multiple clinical specialties. Change of life style, strenuous physical activity and pharmacotherapy are part of conservative treatments. Patients are treated more efficiently by minimally invasive endoscopic procedures or bariatric surgery depending on starting body mass index score. Implantation of intragastric balloons is conceptually simple method of obesity treatment. Modern devices as Bio-Enterics intragastric balloons (BIB), (Inamed Health, USA) are gaining wide popularity among both patients and physicians. BIB intragastric offers the best gains with individuals ranging BMI from 35 to 40. Efficiency has relative timeline dependance from 85% at 6 months to 24% at 36 months. BIB offers substantial ameliorative influence on obesity comorbidities, particularly cardiovascular risk. Treatment with BIB is also efficient but transient treatment modality in morbidly and superobese individuals to reduce preoperative risks of general and bariatric surgery. Obesity treatment with BIB is well tolerated and safe, offering better quality of life. Nevertheless, due to relative poor results of conservative obesity treatments on long-term follow up further investigations defining new clinical parameters for solving treatment resistance. In order to provide resourcefully individualized approach modern perspectives are focused on endocrine constitutes of obesity. Hormonal effects of BIB treatment in compare to bariatric surgery are potentially interesting for the prospect studies