This work presents the development, validation and application of a novel deconvolution method based on B-splines for analyzing variable-rate reservoir performance data. Variable-rate deconvolution is a mathematically unstable problem which has been under investigation by many researchers over the last 35 years. While many deconvolution methods have been developed, few of these methods perform well in practice - and the importance of variable-rate deconvolution is increasing due to applications of permanent downhole gauges and large-scale processing/analysis of production data. Under these circumstances, our objective is to create a robust and practical tool which can tolerate reasonable variability and relatively large errors in rate and pressure data without generating instability in the deconvolution process. We propose representing the derivative of unknown unit rate drawdown pressure as a weighted sum of Bsplines (with logarithmically distributed knots). We then apply the convolution theorem in the Laplace domain with the input rate and obtain the sensitivities of the pressure response with respect to individual B-splines after numerical inversion of the Laplace transform. The sensitivity matrix is then used in a regularized least-squares procedure to obtain the unknown coefficients of the B-spline representation of the unit rate response or the well testing pressure derivative function. We have also implemented a physically sound regularization scheme into our deconvolution procedure for handling higher levels of noise and systematic errors. We validate our method with synthetic examples generated with and without errors. The new method can recover the unit rate drawdown pressure response and its derivative to a considerable extent, even when high levels of noise are present in both the rate and pressure observations. We also demonstrate the use of regularization and provide examples of under and over-regularization, and we discuss procedures for ensuring proper regularization. Upon validation, we then demonstrate our deconvolution method using a variety of field cases. Ultimately, the results of our new variable-rate deconvolution technique suggest that this technique has a broad applicability in pressure transient/production data analysis. The goal of this thesis is to demonstrate that the combined approach of B-splines, Laplace domain convolution, least-squares error reduction, and regularization are innovative and robust; therefore, the proposed technique has potential utility in the analysis and interpretation of reservoir performance data.

The analysis/interpretation of wellbore storage distorted pressure transient test data remains one of the most significant challenges in well test analysis. Deconvolution (i.e., the "conversion" of a variable-rate distorted pressure profile into the pressure profile for an equivalent constant rate production sequence) has been in limited use as a "conversion" mechanism for the last 25 years. Unfortunately, standard deconvolution techniques require accurate measurements of flow-rate and pressure — at downhole (or sandface) conditions. While accurate pressure measurements are commonplace, the measurement of sandface flowrates is rare, essentially non-existent in practice. As such, the "deconvolution" of wellbore storage distorted pressure test data is problematic. In theory, this process is possible, but in practice, without accurate measurements of flowrates, this process can not be employed. In this work we provide explicit (direct) deconvolution of wellbore storage distorted pressure test data using only those pressure data. The underlying equations associated with each deconvolution scheme are derived in the Appendices and implemented via a computational module. The value of this work is that we provide explicit tools for the analysis of wellbore storage distorted pressure data; specifically, we utilize the following techniques: * Russell method (1966) (very approximate approach), * "Beta" deconvolution (1950s and 1980s), * "Material Balance" deconvolution (1990s). Each method has been validated using both synthetic data and literature field cases and each method should be considered valid for practical applications. Our primary technical contribution in this work is the adaptation of various deconvolution methods for the explicit analysis of an arbitrary set of pressure transient test data which are distorted by wellbore storage — without the requirement of having measured sandface flowrates.

Thesis (Ph. D.)--University of Texas at Austin, 2003. / Supervisors: Kenneth E. Gray and Carlos Torres-Verdín Vita. Includes bibliographical references. Available also from UMI Company.

Thesis (Ph. D.)--University of Texas at Austin, 2001. / Vita. Includes bibliographical references (leaves 261-267). Available also in a digital version from Dissertation Abstracts.

Thesis--Auburn University, 2009. / Abstract. Includes bibliographic references (p.51-52).

The study investigated whether providing autonomy support and implementation intention would enhance participants’ subjective well-being in a counting blessings intervention. One hundred and one senior secondary school students were randomly assigned into four conditions: (1) with both autonomy support and implementation intention; (2) with autonomy support only; (3) with implementation intention only; and (4) without autonomy support and implementation intention (control). They were then instructed to count three blessings daily for two weeks. The results indicated that participants’ positive affect was significantly enhanced by counting blessings intervention with autonomy support; while their life satisfaction and positive affect were significantly promoted by the intervention supplemented with implementation intentions. Implications of the findings were discussed. / published_or_final_version / Educational Psychology / Master / Master of Social Sciences

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In this project we have used Fourier transform infrared spectroscopy to study the photoresponse of two different types of quantum dot-in-a-well infrared photodetectors (DWELL QDIPs). The basic task was to compare the photoresponse of these two detectors, and to study the influence of external resonant laser pumping on the photoresponse. Series of measurements were done at 77K. In the first measurements we investigated the photoresponse for different applied voltages at 77K. In a second run of experiments, we used a 1064 nm infrared semiconductor laser to resonantly pump the fundamental transition of the quantum dots. The results show that by using this additional illumination the photoresponse was dramatically increased by creating additional charge carriers in the quantum dots. This could be used to increase the sensitivity of infrared detectors based on QDs.

This paper investigates how the immigration ratio affects the subjective well-being of native-born Canadians. I use microdata from the Canadian Community Health Survey during the period 2009 to 2010 and employ ordered probit and OLS models to examine this question. The results show that the geographic concentration of immigrants in Canada has a negative effect on native-born Canadians’ subjective well-being. Specifically, an increase of one standard deviation in the immigrant share in each health region is estimated to decrease life satisfaction by 1.28 standard deviation unit for natives. In addition, the effect of the immigration ratio on the life satisfaction of immigrants is significantly negative as well. Results indicate that the current immigrant selection policy in Canada does not benefit both natives and immigrants in the context of subjective well-being. / the effect of immigration on the life satisfaction of native-born Canadians.