George Leo Stegemeier

A method for treating a hydrocarbon containing formation

The present invention provides a method for the production of synthesis gas from a hydrocarbon-containing subterranean formation comprising: providing heat to at least a portion of the subterranean formation such that at least a part of the heated portion reaches the pyrolysis temperature of kerogen, yielding pyrolysis products; collecting pyrolysis products from the subterranean formation; injecting a synthesis gas-generating component into the heated part of the formation, resulting in the production of synthesis gas by reaction of the synthesis gas-generating component with carbonaceous material remaining in the formation; and recovering synthesis gas. The synthesis gas thus produced can be used for Fischer-Tropsch synthesis, manufacture of ammonia, urea, methanol, methane and other hydrocarbons, or used as energy source, e.g. in fuel cells. Carbon dioxide produced in such use of the synthesis gas can be sequestered in the formation.

Simulation and performance prediction of a large-scale surfactant/polymer project

This study presents a performance prediction technique for the response of a large-scale chemical flood. The technique involves the sequential use of a detailed finite difference simulator and a streamtube program. Although approximate, the technique avoids the difficulties usually associated with the independent use of either simulator. 9 refs.

Representing Steam Processes With Vacuum Models

Scaled models of steam processes have contributed significantly to the design and implementation of many field projects. These models provide a means of answering pertinent questions including the effect of (1) injection rate, (2) production pressure, (3) completion interval, (4) pattern size and type, (5) aquifers, (6) heterogeneities, and (7) steam quality. Parameters are presented for scaling up physical model results to full scale and for relating one oil field with another. These relationships are generated by casting the governing equations in dimensionless form. A set of similarity parameters are then determined by inspectional analysis. In physical models, unfortunately, it is not possible to match all of the similarity parameters. Consequently, based on engineering judgment, a set containing a reduced number of parameters called scaling parameters is generated which can generally be matched between scaled model and field prototype. Techniques to implement this scaling are discussed, including a description of the laboratory models, typical materials, and procedures for conducting the experiments. Results of model studies for Mt. Poso and Midway Sunset prototypes are presented. (27 refs.)

Interwell pressure testing for field pilots

Procedures are described, and results are compared with core analyses, for a number of transient pressure experiments that were carried out between wells in a small chemical flood pilot. Tests include: a standard pulse test, a simultaneous pressure buildup and falloff of wells in a five-spot pattern, a reverse pulse test, in which response from a producer was measured at a nearby injector during injection, and production drawdown tests from normally shut-in observation wells during polymer injection and during subsequent waterflood in a nearby injector. Flowing these observation wells provided an effective way to measure in-situ mobilities of injected fluids. For pulse tests, a simplified method for design and interpretation of single pulses is derived from basic equations. Dimensionless functions, representing directional permeability and geometrical mean permeability, are shown to be functions of a single dimensionless time lag of the maximum pressure response. For large dimensionless time lags, the ratio of dimensionless permeabilities approaches the value ..pi..e and simple geometric relationships may be used to predict either compressibility or formation thickness.