I performed manual History Matching on the E-segment of the Norne field based on available production & pressure data. I used the obtained final match for future prediction. I performed Production Optimization by experimenting with increased and decreased water injection rates.

With the increasing number of drilled ultra-extended reach wells and complex geometry wells, the drilling limitation caused by excessive torque and drag forces must be further investigated. The wellbore friction being a main limiting factor in extended reach well needs to be studied with the new developed models.This master thesis presents an application of the new 3-dimentional analytical model developed by Bernt S. Aadnøy in the synthetic test and four real wells. Quite diverse wellbore trajectory and depth has been chosen for a better evaluation and comparison of the model with the measured data. In order to investigate the potential and limitation of the model, torque and drag analysis during the different operations such as tripping in, tripping out, rotating off bottom, combined up/down were investigated. An application of the analytical model for wellbore friction analysis in the actual wells is very time consuming and requires a lot data/input manipulation. As a part of the thesis assignment, it was required to create simplified means for application and testing the analytical model. With visual basic application in Excel a simple torque and drag simulator was created purely based on the analytical model simple solution. Along with the analytical model the master thesis includes Wellplan software for torque and drag analysis in all the included test and actual wells. Along with this, the project has a brief literature study of 3D analytical model and torque and drag concept in general. The analytical model gives a reasonable torque and drag results. Based on comparison between the model and actual measurement, it has been observed that the analytical model simple solution in some cases may not precisely describe wellbore friction analysis. The discrepancy between Wellplan and the analytical model prediction occurs during the tripping in operations. Being a strong function of tension/compression in the drill string the analytical model for more accurate torque and drag prediction requires an application of the complete solution. The main challenge for this model is the complexity of its full application. There is an uncertainty regarding the model application in conjunction with drillstring effective tension. For the actual well application it is time consuming and requires drillstring effective tension analyzing which make the model disable for the real time analysis.The analytical model must be further investigated by application in the real well with good quality of measured data.

This research is a simulation study to improve total oil production using ASP flooding method based on simulation model of Norne field C-segment. The black oil model was used for simulations. Remaining oil in the reservoir can be divided into two classes, firstly residual oil to the water flood and secondly oil bypassed by the water flood. Residual oil mainly contains capillary trapped oil. Water flooding only is not able to produce capillary trapped oil so that there is a need for additional technique and force to produce as much as residual oil. One way of recovering this capillary trapped oil is by adding chemicals such as surfactant and alkaline to the injected water. Surfactants are considered for enhanced oil recovery by reduction of oil–water interfacial tension (IFT). The crucial role of alkali in an alkaline surfactant process is to reduce adsorption of surfactant during displacement through the formation. Also alkali is beneficial for reduction of oil-water IFT by in situ generation of soap, which is an anionic surfactant. Generally alkali is injected with surfactant together. On the other hand, polymer is very effective addition by increasing water viscosity which controls water mobility thus improving the sweep efficiency.In the first place, ASP flooding was simulated and studied for one dimensional, two dimensional and three dimensional synthetic models. All these models were built based on C-segment rock properties and reservoir parameters. Based on test runs, well C-3H was selected and used as a main injector in order to execute chemical injection schemes in the C-segment. Five studies such as polymer flooding, surfactant flooding, surfactant-polymer flooding, alkaline-surfactant and alkaline-surfactant-polymer flooding were considered in the injection process and important results from simulator were analyzed and interpreted. Sensitivity analyses were done especially focusing on chemical solution concentration, injection rate and duration of injection time. The polymer flooding project in this study has shown a better outcome compared to water flooding project. Economically best ASP solution flooding case is the flooding with concentration of alkaline at1.5kg/m3, surfactant at 15kg/m3 and polymer at 0.35 kg/m3 injecting for 5 years. AS flooding case for 4 years with alkali concentration at 0.5kg/m3 and surfactant concentration at 25 kg/m3 gave highest NPV value. It was found that surfactant flooding has a promising effect and it is more profitable than polymer flooding for the C segment in terms of NPV. Economic sensitivity analysis (Spider diagram) for low case, base case and high case at different oil prices, chemicals prices, and discount rate were also presented. It was found that change in oil price has significant effect on NPV compared to other parameters while polymer price has the least effect on NPV for high and low cases.

This study presents a detailed analysis of producing gas-oil ratio performance characteristics from conventional reservoir to unconventional reservoir. Numerical simulations of various reservoir fluid systems are included for comparison. In a wide sense of the word, the term of unconventional reservoir is including tight gas sand, coal bed methane, gas hydrate deposits, heavy oil gas shale and etc. In this study we specify the unconventional reservoir to only mean the low and ultra low permeability reservoir, which is including tight or shale reservoir. As an emerging research topic in the E&P industry, shale reservoir’s long-term well performance characteristics are generally not well understood (Anderson et al. 2010). Research methods and techniques for conventional reservoir are usually directly used in this unconventional reservoir analysis. These methods, however, have proven to be too pessimistic (Anderson et al., 2010). Fit-for-purpose approaches or solutions should be introduced in this new topic. Recently, hydraulic fracturing treatment is commonly used in the low matrix permeability reservoir to attain an economic production rate. The difference of well production performance between conventional reservoir and unconventional reservoir is not well known. In this study, we are trying to give a quantitative analysis in order to answer this question.In this study, a “generic” reservoir from field data with constant reserves and size were assumed. This reservoir model is homogeneous and of constant porosity, permeability and initial water saturation. In order to compare the production performance, fluid systems are varied from volatile oil to near critical oil, to gas condensate and to wet gas. The permeability of the reservoir model is also designed from high (conventional reservoir) to ultra low (unconventional), which ranges from 101 to 10-5 mD. Influence from fracture is especially considered because fractures in the low permeability reservoir provide a high conductivity that connects the reservoir matrix to the horizontal well. Fractures in the model are designed with identical geometrical characteristics (length, thickness) and of inner homogeneous properties (porosity, permeability).A black-oil model is used for each reservoir, and its PVT properties are generated with a 31 components EOS model using Whitson-Torp procedure (Whitson et al., 1983). Reservoir fluid systems equilibrium calculation in the black-oil model is done using the initial gas-oil ratio. We have compared the well’s production performance for each fluid system.Based on the industry experience, two standards are used in reservoir simulation control: gas production rate and cumulative revenue. The gas production rate with 10 ×106 ft3/day in the first 10 days or the cumulative revenue equal to 5 ×105 USD from the first 10 days is set as the standard for the commercial well rate. All of these simulations are run under the control of these two types which have just been mentioned. A case of liquid rich gas reservoir is analyzed systematically, to compare its production performance when reservoir permeability is changed from high to low. We are interested in how much oil or gas condensate can be extracted from the “reservoir” if same initial fluids in the reservoir but of a different permeability. This study is useful and practical, particularly for the industry in the era of “high” oil price and “low” gas price in North America.The simulation results show that we can extract more liquid from the reservoir if the matrix permeability is higher, particularly for the reservoir with initially large oil contents (volatile oil reservoir, near critical reservoir and gas condensate reservoir). Fracturing treatment in unconventional reservoir is required to attain an economic production rate. We also realize that for the required number of fractures and reservoir’s matrix permeability, there exists linear correlation in log-log plot in the low-permeability reservoir. In this study, the unique optimization software Pipe-It and reservoir simulator SENSOR are used. Optimal simulation results of permeability combination are obtained by the module Optimizer in Pipe-It.

In this study, based on the work of Vogel, we generated the Inflow Performance Relationship (IPR) curves and its dimensionless form at any stage of depletion using black-oil simulator results. The IPR was generated for horizontal well with gas and water coning problems, producing from thin oil reservoir sandwiched between gas cap and aquifer. Two empirical IPR equations adopted from SPE paper by Whitson was also presented here. The first empirical relationship was developed based on simulated data for each reservoir pressure (stage of depletion) while the second relationship was developed based on all generated data.A fully implicit black-oil Cartesian model with total grid number of 1480 and 150 ft total thickness was used as reservoir model. The horizontal well extends through the full length of reservoir in y-direction with only one grid number along the horizontal section which makes the model a 2D problem. Sensor reservoir simulator and Pipe-It software were utilized to generate the IPR data.This work also includes a sensitivity study to understand the effect of several parameters to gas and water coning behavior, well placement optimization, coning collapse study, and the effect of coning to maximum well production rate. In coning collapse study, a relationship between flowing bottom-hole pressure and reservoir pressure when the cone collapse is provided in graphical form. This could be useful in field application where chocking the well to lower flowing bottom-hole pressure has become one alternative to reduce coning problems.

Water coning is a complex phenomenon that depends on a large number of variables which include among others: production rate, perforation interval, mobility ratio, capillary pressure, etc. Its production can greatly affect the productivity of a well and the reservoir at large. In fractured reservoirs, the phenomenon is more complex owing to the high permeability of the fractures in the porous media. With this complexity in mind, water coning behaviour in fractured reservoir was studied by simulating a reservoir supported by a strong aquifer using ECLIPSE-100 Black-Oil Simulator. The water cut (WCT), oil production rate (OPR) and water saturation (BWSAT) at the producing interval (Block 1, 1, 7) were used to evaluate the coning phenomenon in a fractured reservoir. In the course of the study, sensitivity analyses on the modelled reservoir’s anisotropy ratio (kv/kh), production rate (q), storativity capacity (ω), fracture width (b) and fracture permeability (kf) were conducted to evaluate their effect on coning behaviour in fractured reservoir. The results obtained depict that while the anisotropy ratio is very significant in water cut and water saturation at the perforating interval it has no adverse effect on oil production rate. It was however, observed that the water cut and oil production rate decreased as the production rate (q) increased. Furthermore, the water cut, oil production rate and water saturation (BWSAT) from the fractured reservoir is sensitive to the storativity capacity (ω) depending on the fracture porosity (φf). Conversely, the fracture’s width (b) and permeability (kf) have no significant effect on the coning behaviour of the modelled fracture reservoir. However, anisotropy ratio (kv/kh), production rate as well as storativity capacity (ω) are significant parameters in evaluating coning phenomenon in fractured reservoirs.

To determine the carrying capacity of the drilling fluid, also determine the settling velocities of the drilling cuttlings. To produce the Reynold's number experimentally.

This study was undertaken to assess rates and timing of mortality and hatchability, to identify pathological changes and compare them to those observed in chicken embryos, and to determine whether mallard duck chorioallantoic membrane (CAM) is a target organ of toxicity of Prudhoe Bay crude oil (PBCO). Mortality and hatchability were determined in embryos exposed to 10[mu]l of PBCO on days 3, 6, 9 and 12 of incubation. Pathological changes in embryos and the CAM, hematological parameters and body and plasma calcium concentration were assessed in live embryos exposed to PBCO on day 12. Oil-exposed embryos had high mortality, low hatchability and high prevalence of pathological changes. Mortality was characterized by initial death that coincided with development and maturation of the CAM and a sublethal effect that resulted in live, mature embryos, which were unable to hatch. This mortality at hatching contributed greatly to total mortality. Lesions included hepatic and renal necrosis, liver enlargement, subcutaneous edema, reduced body weight and ratio of body weight to fresh egg weight, short crown-rump, third toe and metatarsal lengths, depletion of lymphocytes in the bursa of Fabricius, renal hematopoiesis, and diffuse changes in the CAM which included necrosis and hyperplasia, of chorionic epithelium, soft swelling of mesenchymal cells, hemorrhages and reduced vascular density. There also were high proportions of reticulocytes and polychromatophilic and primary erythrocytes. Prevalence of lesions in the CAM was greatest during the stage of acute toxicity, suggesting that injury to the CAM may have a role in acute oil. toxicity. The distribution of lesions in the CAM suggests a direct effect on the CAM cells of toxic components or their metabolites. Injury to the CAM did not affect its role in mobilization of calcium from the eggshell. Body and plasma calcium in oil-exposed and control embryos were not different. Embryos exposed to PBCO did not develop anemia nor any damage to the red blood cells. The spectrum of morphological changes in oil-exposed embryos suggests retarded and altered development The rate and timing of mortality and pathological changes in oil-exposed mallard embryos were similar to those reported in oil-exposed chicken embryos.

Twenty-two sediment samples were collected from Kaohsiung Harbour, and it¡¦s neighboring coastal area, Taiwan and analysed for a suite of n-C10-C35 aliphatic hydrocarbons and fifteen polycycilc aromatic hydrocarbons (PAHs). The average total concentration of n-alkanes was 4.327 £gg/g dry wt. (0.461-22.601 £gg/g dry wt.) and PAHs was 0.588 £gg/g dry wt. (0.088-1.75 £gg/g dry wt.). The highest n-alkanes and PAHs concentrations were recorded in samples from D and A stations in Kaohsiung Harbour ; stations D and A are near the outlets of Chyan-Jenn and Jen-Ai rivers, respectively. The sources of n-alkanes are probably contributed form origins of petrogenic, biogenic and higher plants according to the value of CPI (carbon preference index), chromatogram of UCM (unresolved complex materials), and n-C16 ratio etc.; while PAHs were contributed mainly from combustion in coastal areas and petrogenic in harbour areas based on the ratios of total combustion and LMW/HMW ratios. Overall, sediment concentrations of n-alkanes and PAHs in Kaohsiung coastal area were similar to literature in the world. The potential for biological effects due to PAHs is found to be low based as their individual PAHs concentrations are in general lower than effects most existed sediment quality guidelines, except Acenaphthaene, Anthracene, Benzo[a]anthracene, and Fluorene.

Biodegradation of petroleum hydrocarbon can be an effective treatment method applied to control oil pollution in both fresh water and marine environments. Hydrocarbon degraders, both indigenous and exogenous, are responsible for utilizing petroleum hydrocarbon as their substrate for growth and energy, thereby degrading them. Biodegradation of hydrocarbons is often enhanced by bioaugmentation and biostimulation depending on the contaminated environment and the competence of the hydrocarbon degraders present. An evaluation of the performance of the biological treatment of petroleum hydrocarbon by the hydrocarbon degrading microbes at the Brayton Fire School??s 4 million gallon per day (MGD) wastewater treatment plant was the main research objective. Samples were taken for two seasons, winter (Nov 03 ?? Jan 03) and summer (Jun 04 ?? Aug 04), from each of the four treatment units: the inlet tank, equalization tank, aeration tank and the outfall tank. The population of aliphatic hydrocarbon degraders were enumerated and nutrient availability in the system were used to evaluate the effectiveness of on-going bioaugmentation and biostimulation. Monitoring of general effluent parameters was conducted to evaluate the treatment plant??s removal efficiency and to determine if effluent discharge was in compliance with the TCEQ permit. The aeration tank is an activated sludge system with no recycling. Hydrocarbon degraders are supplied at a constant rate with additional nutrient supplement. There was a significant decrease in the population of microbes that was originally fed to the system and the quantity resident in the aeration tank. Nutrient levels in the aeration tank were insufficient for the concentration of hydrocarbon degraders, even after the application of dog food as a biostimulant. The use of dog food is not recommended as a nutrient supplement. Adding dog food increases the nitrogen and phosphorus concentration in the aeration tank but the amount of carbon being added with the dog food increases the total chemical oxygen demand (COD) and biochemical oxygen demand (BOD). An increase in the concentration of total COD and BOD further increases the nitrogen and phosphorus requirement in the system. The main objective of supplying adequate nutrients to the hydrocarbon degraders would never be achieved as there would be an additional demand of nutrients to degrade the added carbon source. This research study was conducted to identify the drawbacks in the treatment plant which needs further investigation to improve efficiency.