Geology, geography and global energy

Scientific and Technical Journal

Geological Complications Encountered when Drilling Prospecting Wells in the Volga-Akhtubinsk Flood Plain

2012. №4, pp. 44-50

Almamedov Yalchin L.O. - Post-graduate student, Astrakhan State University, 20a Tatishchev st., Astrakhan, Russian Federation, 414000,

Fadeev Mikhail V. - Student, Astrakhan State University, 20a Tatishchev st., Astrakhan, Russian Federation, 414000,

The article relates that several major problems have arisen when drillers have wired productive wells found in Permian age salt deposits. It adds that the wells were constructed in salt deposits despite the numerous complications attached to the process of passing unstable clay and drilling salts, and using the deposits’ attachment casing. The paper proposes that in choosing the feasibility of structural borehole drilling sites, consideration be paid in the future to the presence of exploratory design paths. The primary tool designed to address these challenges, continuous multi-level geotechnical monitoring of well wiring, is based on a geological and hydrodynamic model of the field; it needs to be followed by seismic and petro-physical control of the drilling process. The critique claimed that two factors – analysis of wells drilled in adjacent areas and careful monitoring of drilling data – would enable the drillers to select the optimum mud weight and pass the salt and Filippovskiy horizon, as well as to lower the casing. The construction results have served to explain the reasons behind the unstable state of the wellbore, which has isolated interval breeds that are prone to stress. During drilling, the mud density has been specified and the appropriate chemical treatment established. As a pre-condition to drilling, casing strings have been run according to the results of the geographic information system (GIS) by adjusting the depth of the descending columns, pipe sizing and wellbore location. The document said that prior to drilling exploratory wells important problems – such as opening the reservoir and coring – should have been resolved. Meanwhile, ongoing downhole geophysical and hydrodynamic investigations are exploring the reservoir properties and the level of productive reservoir gas-water contacts.

Key words: oil and gas,exploration wells,rivers,migration,salt dome,deposits,folds