Time Estimation of Future Plug and Abandonment Operation at Brage Field

Master's thesis in Petroleum engineeringProduction of oil on the Norwegian continental shelf started in the early 70’s. Many of these fields are now reaching the end of their production time. The industry is now awaiting a “plug wave” in the not too distant future. Decommission is a time-consuming procedure, and the cost of P&A can end up being 25 % of the total cost of the well. The task given from Wintershall was to plan P&A operation by setting a dual barrier plug against the creeping clay in the Hordaland formation. The Hordaland green clay will creep in and seal around the casing and create a bonding with the casing. This method has saved operators on the Norwegian continental shelf for millions of NOK, by avoiding milling or squeeze cement job. All the wells at Brage require permanent P&A in order to control subsurface pressure and prevent the free flow of pore fluids to the seabed. The wells at Brage was categorized depending on the different casing design. The objective was to determine the time for P&A for every category. There were three different casing designs that stood out: pre-drilled wells, production liner with tie-back casing and simplified casing design. The most likely time for plugging the 40 wells at Brage is estimated to be around 3 years. The time estimate is done with the technology available today. In the future there might be new technology that will enable the operator to P&A the field in a more cost-effective way. Many service companies are working on developing tomorrows P&A solution. Some of the new technologies will be presented and discussed in this thesis, together with the use of formation as a barrier

New animism : new perspectives on contemporary relgiousity and political ecology through activism rooted in a non-dual reality

Master's thesis in global studies. School of Mission and Theology, May 2015MV 17 S

Heterologous Transplantation, Chromosome Analyses, and DNA Measurements of the Human Carcinoma Tissue Culture Line, H.Ep. #2

The human epidermoid carcinoma No.2 (H.Ep. #2), which had been kept continuously in tissue culture since 1953, was transplanted into adult, conditioned golden hamsters. Morphologically, the transplanted tumors resembled closely the original tissue from the patient. Chromosome analyses were performed on two series of H.Ep. #2 cells, both originating from Fjelde stock cultures. The First series comprised the first stock culture from Fjelde (TCF), the corresponding First hamster tumor line (H.Ep. #2/H1), and material from the latter brought back into tissue culture (H.Ep. #2/H1-TC). The second series included the second tissue culture material (H.Ep. #2/TC2) and the ensuing second hamster tumor line (H.Ep. #2/H2). Chromosome numbers of cells of the first series varied between 69 and 80, with a large peak at 74-75 and a smaller peak at 77. Four marker chromosomes were present. In the second series, a large peak was found at 69-70 and a smaller peak at 74-75. Besides the 4 markers from the First series, the cells within these peaks possessed 2 new markers, each of them characteristic for one of the peaks. The different peaks in the frequency distribution of the chromosome numbers were interpreted as representing 2 stemlines. In the first series this assumption was based on chromosome numbers only, whereas in the second series it was corroborated by the presence of the individual marker chromosomes. DNA was measured on Feulgenstained nuclei of H.Ep. #2 cells grown in vivo and in vitro. Both tumor cell lines showed their DNA values to be aggregated in two peaks: one around 3.5c and the other around 7c. Thus a correlation was established between the amount of DNA and the hypertriploid chromosome number of H.Ep. #2 cell

CO2 Dissolution and Convection in Oil at Realistic Reservoir Conditions: A Visualization Study.

CO2 convective mixing has been extensively studied for CO2 dissolution in saline water but very limited with the presence of oil. The objective of this work was to visually study the supercritical CO2 (sCO2) dissolution and convective mixing into oil at realistic reservoir temperature and pressure conditions with and without the presence of porous media. A specially designed high-pressure 2D-cell was used to investigate the sCO2 mixing into oil phases. Schlieren imaging method was used as the visualization method. The experiments were carried out at 100 bar and 50 °C using n-octane, n-decane, and crude oil as the main oils. Porous media with different permeability was prepared using glass beads. Convective fingering was found to accelerate the mixing of CO2 with n-octane and n-decane. It was not possible to visualize the CO2 convective fingering in crude oil due to the low opacity of the oil phase. The CO2 dissolution into oil phases was quite instantaneous and fast without the presence of porous media. The swelling of oil was measured as 55%, 50% and 11% for n-decane, n-octane and crude oil respectively without the presence of porous media. Boundary effects were affecting the CO2 mixing due to the circular shape of the 2D-cell. Having a water layer below the oil layer tends to dampen the CO2 transport from the oil phase to the water phase. CO2 dissolution into oil saturated porous media was slower compared to that without the presence of porous media. The mixing of CO2 was faster at higher permeability than at lower permeability. Visualization of CO2 convective mixing/fingers inside oil-saturated porous media using a Hele-Shaw cell yet to be achieved experimentally.publishedVersio

Pressure Build-Up in Closed Wells During Kick Migration and Fluid Compressibility Effects

If a kick is migrating in a closed well, this will lead to pressures building up in the well. It has earlier been shown that for Non-Newtonian fluids, suspension effects will make it impossible to deduce a unique gas velocity from the pressure build-up behavior. In this work, it will be shown that also for Newtonian fluids, the pressure build-up will depend on both kick size and well volumes. Both very small kicks sizes typically seen in MPD operations and larger kick sizes handled in conventional well control operations will be considered. It will be demonstrated that both the shape of the pressure build-up and the final pressure levels achieved will vary significantly. It is especially when considering very small kick sizes that one starts to see large changes in the profile of the pressure build-up. The main reason for the differences is related to the fact that the liquid phase is compressible and this will again have consequences for how much a gas kick can expand and what pressures it can bring to surface. An analytical model will be developed that shows directly which parameters have impact on the pressure build-up behavior. Simple closure laws for gas density, fluid density and gas slip will be chosen. The model will be verified against two transient models which are based on the Drift-Flux formulation. It is demonstrated that the pressure build-up and final pressure level will depend on initial kick volume, initial fluid volume, liquid compressibility and fluid density. The effect of numerical diffusion when comparing the two transient models will also briefly be discussed. The purpose of the paper is to increase fundamental knowledge about two phase flow dynamics and show that an analytical model for the situation considered here can give results that are comparable with the results achieved with more complex transient flow models.acceptedVersio

Moisture in compact roofs

Fuktproblemer er et av de mest kompliserte områdene innenfor bygningsfysikken i dag. I denne rapporten er det gjort vurderinger av materialvalg og løsninger når man bygger med kompakte tak. Det er også presentert typiske fuktskader i kompakte tak og utbedrende tiltak for disse. I denne oppgaven er det brukt metoder som litteraturstudie, intervjuer og casestudie. Moisture problems are one of the most complicated areas in building physics today. This thesis has made assessments of materials and solutions when building with compact roofs. It is also presented typical moisture damage in compact roofs and corrective action for these. This thesis uses methods like literature review, interviews and case study