Scientists propose cutting the cost of studying gas fields with 'tornado experiment' method

The essence of the method

To estimate how much gas can be extracted from a field, engineers build computer models. Such models require hundreds of parameters: porosity and permeability of rocks, reservoir pressure, water properties. Determining them requires drilling wells, taking rock samples, and laboratory analyses, which involves time and expense. The researchers asked whether every field really needs all parameters studied equally deeply, reports Kun.uz.

How the study was conducted

The scientists analyzed data on 66 gas deposits in Western Siberia. They used the 'tornado experiment' method: each geological parameter was varied in the model one at a time, and its effect on the production forecast was recorded. The method's name has nothing to do with natural tornadoes: the analysis results are displayed on funnel-shaped diagrams, where the factors with the greatest influence on the forecast are shown as the widest bars. This helps separate key parameters from secondary ones.

Different layers — different priorities

It turned out that priority factors differ across geological layers. According to project participant Artyom Yeliseyev, in the relatively shallow, loose and porous Cenomanian layers, the properties of the underlying water and how gas and water move between rocks are important. In such fields, water may enter wells prematurely, and some gas may remain in the reservoir. In the deeper Hauterivian layers with denser rocks, other tasks come to the fore: accurately estimating the gas volume and determining which layers actually contribute to production.

The algorithm and software testing

Based on the results, the scientists proposed an algorithm that determines, for each field, which measurements must be carried out and which can be reduced or skipped entirely. For example, at some fields pressure monitoring needs to be intensified and more rock samples taken, while at others the focus should be on hydrodynamic studies of fluid and gas movement in wells. The savings are expected to come from more precise planning of the field study program: the authors claim this approach reduces redundant research costs, without degrading forecast accuracy. The study also tested Russian software: according to the scientists, in hundreds of computational scenarios its speed and accuracy were compared with foreign counterparts, and it was not inferior to them.

Significance of the work

The development concerns companies engaged in gas exploration and production: the algorithm makes it possible to determine in advance which expensive measurements at a particular field are truly necessary and which can be abandoned without losing forecast quality. The practical consequence is a reduction in the amount of drilling, sampling, and laboratory analyses when planning field development. However, the publication does not contain data on where and when the method will be implemented, nor on the specific amount of savings.