The main objective of this research is to devise a risk-based methodology for developing emergency operation schedules (EOS). EOS are decision tools that provide guidance to reservoir operators in charge of making real-time release decisions during major flood events. A computer program named REOS was created to perform the computations to develop risk-based EOS. The computational algorithm in REOS is divided in three major components: (1) synthetic streamflow generation, (2) mass balance computations, and (3) frequency analysis. The methodology computes the required releases to limit storage to the capacity available based on the probabilistic properties of future flows, conditional to current streamflow conditions. The final product is a series of alternative risk-based EOS in which releases, specified as a function of reservoir storage level, current and past inflows, and time of year, are associated with a certain risk of failing to attain the emergency operations objectives. The assumption is that once emergency operations are triggered by a flood event, the risk associated with a particular EOS reflects the probability of exceeding a pre-established critical storage level given that the same EOS is followed throughout the event. This provides reservoir operators with a mechanism for evaluating the tradeoffs and potential consequences of release decisions. The methodology was applied and tested using the Addicks and Barker Reservoir system in Houston, TX as a case study. Upstream flooding is also a major concern for these reservoirs. Modifications to the current emergency policies that would allow emergency releases based on the probability of upstream flooding are evaluated. Riskbased EOS were tested through a series of flood control simulations. The simulations were performed using the HEC-ResSim reservoir simulation model. Rainfall data recorded from Tropical Storm Allison was transposed over the Addicks and Barker watersheds to compute hypothetical hydrographs using HEC-HMS. Repeated runs of the HEC-ResSim model were made using different flooding and residual storage scenarios to compare regulation of the floods under alternative operating policies. An alternative application of the risk-based EOS in which their associated risk was used to help quantify the actual probability of upstream flooding in Addicks and Barker was also presented.

The Capacitance Resistance Model (CRM) is a reservoir model based on a data-driven approach. It stems from the continuity equation and takes advantage of the usually abundant rate data to achieve a synergy of analytical model and data-driven approach. Minimal information (rates and bottom-hole pressure) is required to inexpensively characterize the reservoir. Important information, such as inter-well connectivity, reservoir compressibility effects, etc., can be easily and readily evaluated. The model also suggests optimal injection schemes in an effort to maximize ultimate oil recovery, and hence can assist real time reservoir analysis to make more informed management decisions. Nevertheless, an important limitation in the current CRM model is that it only treats the reservoir flow as single-phase flow, which does not favor capturing physics when the saturation change is large, such as for an immature water flood. To overcome this limitation, we develop a two-phase flow coupled CRM model that couples the pressure equation (fluid continuity equation) and the saturation equation (oil mass balance). Through this coupling, the model parameters such as the connectivity, the time constant, temporal oil saturation, etc., are estimated using nonlinear multivariate regression to history match historical production data. Incorporating the physics of two-phase displacement brings several advantages and benefits to the CRM model, such as the estimation of total mobility change, more accurate prediction of oil production, broader model application range, and better adaptability to complicated field scenarios. Also, the estimated saturation within the drainage volume of each producer can provide insights with respect to the field remaining oil saturation distribution. Synthetic field case studies are carried out to demonstrate the different capabilities of the coupled CRM model in homogeneous and heterogeneous reservoirs with different geological features. The physical meanings of model parameters are well explained and validated through case studies. The results validate the coupled CRM model and show improved accuracy in model parameters obtained through the history match. The prediction of oil production is also significantly improved compared to the current CRM model. A more reliable oil rate prediction enables further optimization to adjust injection strategies. The coupled CRM model has been shown to be fast and stable. Moreover, sensitivity analyses are conducted to study and understand the impact of the input information (e.g., relative permeability, viscosity) upon the output model parameters (e.g., connectivity, time constants). This analysis also proves that the model parameters from the two-phase coupled model can combine both reservoir compressibility and mobility effects. / text

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The term upscaling and determination of pseudo curves, or effective parameters, used on a coarse-scale simulation grid are related to the complex and extensive problems associated with reservoir studies. The primary strategy mainly focuses on having a good physical and practical understanding of the particular processes in question, and an appreciation of reservoir model sensitivities. Thus the building of the reservoir simulation models can be optimally determined.By concentrating on the modelling and upscaling gas injection for Enhanced Oil Recovery (EOR) process, which includes Interfacial Tension (IFT) and the amicability effect, a new effective and efficient algorithm of upscaling will be investigated and determined by using several upscaled parameters. The sensitivities of these determined coarse scale parameters (i.e. porosity, absolute and relative permeability and capillary pressure), will also be studied through a history matching of the existing field.

Abstract Burrow-associated diagenetic alteration and eventual reservoir quality parameters such as porosity and permeability may be altered due to reorganization of the sediment fabric associated with animal burrowing, or result from heterogeneous cement distribution influenced by the bioturbate texture. Petrographic analysis has significant application in recognizing burrow-associated porosity characteristics in marine sandstones. Petrographic analysis can provide mineral identification due to diagenetic chemical alterations and textural evidence regarding cementation history that can lead to more accurate hydrocarbon target interpretations. Overlooking burrow structures may lead to misinterpretations of permeability streaks in hydrocarbon reservoirs. This may be extremely important for reservoirs where slight permeability variations have an effect on hydrocarbon reserve calculations. Understanding biogeochemical reactions and burrow-associated diagenesis that ultimately control reservoir quality is necessary if production from ancient bioturbated marine sandstone reservoirs is to be optimized.

A detailed laboratory study of sandstone samples from outcrops and conventional core samples from the Maastrichtian-Paleocene Scollard-age fluvial strata in the Western Canada foredeep was undertaken to investigate the reservoir characteristics, burial depth history, and sandstone diagenesis. The sandstones are predominantly litharenites and sublitharenites, which accumulated in a variety of fluvial environments. The porosity of the sandstones is both syn-depositional and diagenetic in origin. The potential of a sandstone to serve as a reservoir for producible hydrocarbons is strongly related to the sandstones diagenetic history. Detailed study of the distribution of authigenic minerals of the Scollard sequence suggests that the diversities in the pattern distribution of authigenic clay minerals in the regions are not random but they coincide with the burial depth of these strata and has a well-defined relation to the sequence stratigraphic framework The general absence of dickite, coupled with limited conversion of smectite into illite in the Scollard sandstones, suggests crystallization at a depth less than 1.5 km. In contrast, the occurrence of blocky dickite, fibrous illite and chlorite in the Coalspur and Willow Creek sandstones, coupled with albitized feldspars and quartz cement, suggests that sandstones there underwent a maximum burial depth greater than 3 km. It has been observed that kaolin mineral content increases in sandstones lying below subaerial unconformities, which mark the most significant stratigraphic hiatuses and hence the sequence boundaries in fully fluvial successions. This study demonstrates the effects of burial depth and paleoclimate on pore-water chemistry, which in turn, influenced the mineralogy and the distributions of authigenic minerals in the sandstones. The 13C and 18O compositions of pedogenic carbonate nodules from the Willow Creek Formation associated with the red shale host sediments have been used as a paleoclimate and paleoenvironmental proxy. The isotopic composition of nodules suggests that these formed during drier conditions when C3 vegetation prevailed at the site. The predominance of smectite and illite in fines and the poor floral content point to a low seasonal rainfall in a semi-arid climatic environment.