OREANDA-NEWS. Specialists have completed a seven-month survey of the Syderiai geological structure as part of Lietuvos Energija, AB project to construct an underground natural gas storage facility. The survey data will undergo a thorough analysis, which should indicate whether Syderiai geological structure is suitable for the construction of strategic significance facility.

Drilling works in the first well were initiated in mid-September last year. Over seven months, four exploratory wells were drilled at the Syderiai geological structure in Juciai and Rudupiai villages (Telsiai district). In the vicinity of Juciai village, one vertical well (1532 metres in depth) and two re-entry wells (1461 and 1528 metres in depth) were drilled. A single 1562-metre-deep vertical well was drilled in Rudupiai.

“All the geological and geophysical surveys that were scheduled in the project enabling to assess key characteristics of the geological structure were completed in time and in accordance with environmental regulations. Analysis of the obtained data will demonstrate whether natural gas can be stored within the structure at the depth of approximately 1450 metres,” says Tomas Kuciauskas, Manager of the Syderiai gas storage facility project. According to him, three main conditions must be met: the capacity and filtration properties of the reservoir must be fit to store gas, protective layer covering the reservoir and the fault to which geological structure is confined must be impermeable.

The drilling works were performed jointly by a group of companies consisting of Minijos Nafta JSC, LL investicijos JSC and Diament, a Polish drilling and survey company. The contracts were signed at the beginning of August 2012. Since scheduled surveys have been already completed, drilling equipment at the drilling sites is being dismantled, site management works are being carried out, and drilling-survey reports are being prepared which should be presented in May 2013.

In order to process and assess the data collected, a tendering procedure for the supply of services of reinterpretation of seismic data and development of a preliminary model of the reservoir has been initiated. Processing of the complete set of data on the Syderiai geological structure collected in 2010–2013 will lead to a development of the reservoir model, which will enable to assess the characteristics of the gas storage. The model will be used as a basis for the estimation of the potential gas volumes to be stored in the reservoir and for the development of potential gas injection and production scenarios. Furthermore, the number and types of requisite wells will be determined and financial investment estimates required for the project will be prepared.

It is expected that the winner of the tender for the seismic data reinterpretation and modelling services will be known in May and all the works will be completed by the end of this year. Once the final results of the surveys are released, public meetings with Telsiai district community will be held.