An alternative approach to match field production data from unconventional gas-bearing systems

Nowadays, the unconventional gas-bearing system plays an increasingly important role in energy market. The performances of the current history-matching techniques are not satisfied when applied to such systems. To overcome this shortfall, an alternative approach was developed and applied to investigate production data from an unconventional gas-bearing system. In this approach, the fluid flow curve obtained from the field is the superposition of a series of Gaussian functions. An automatic computing program was developed in the MATLAB, and both gas and water field data collected from a vertical well in the Linxing Block, Ordos Basin, were used to present the data processing technique. In the reservoir study, the automatic computing program was applied to match the production data from a single coal seam, multiple coal seams and multiple vertically stacked reservoirs with favourable fitting results. Compared with previous approaches, the proposed approach yields better results for both gas and water production data and can calculate the contributions from different reservoirs. The start time of the extraction for each gas-containing unit can also be determined. The new approach can be applied to the field data prediction and designation for the well locations and patterns at the reservoir scale.

Studies on the Expanded Sequence Matrix and its Application in Flowshop Layout

Based on the analysis of current kinds of sequence matrixes, Type 1 and Type 2, an expanded and refined sequence matrix was proposed. Then, based on the optimized expanded sequence matrix, an improved sequence matrix was brought forward, which could be easily written in a normalized form and whose calculation was simple and convenient. With operational rules of combined sequence matrixes defined, this expanded sequence matrixes can also be applied to the problems of mixed production lines. Finally, the improved matrix was successfully applied to an example of flowshop balancing problem, and it was implemented in the Excel environment in an automatic computing way.