Liquidation of Oil Prospecting Wells
Over-all Investigation and Technology Development for Liquidation of At-Conservation Oil Prospecting Wells in the Area of Inundation and Underflooding by the Caspian Sea in Mangystau Oblast of the Republic of Kazakhstan
Tech Area / Field
- ENV-RED/Remediation and Decontamination/Environment
- ENV-WPC/Water Pollution and Control/Environment
3 Approved without Funding
Limited Partnership Company «Astana N-Tech», Kazakstan, Astana
- Kazakh National University / Center of Physical and Chemical Methods of Analysis, Kazakstan, Almaty\nMangystau-Monitoring Ltd., Kazakstan, Aktau
- Middlesex University / School of Health and Social Sciences, UK, London\nNatural Resources Canada / CANMET Energy Technology Centre-Devon, Canada, AB, Devon
Project summaryObjective of the Project is to perform over-all environmental and technical works on assessment of technical conditions of underflooded and inundated wells, investigation of their influence on environment and development of rehabilitation measures for liquidation of inundated wells in Mangystau oblast of the Republic of Kazakhstan.
In total on the territory of Kazakhstan there are more than 10 thousand oil-and-gas wells and about 360,000 geological and hydrogeological wells drilled by organizations of the Ministry of Geology and the Ministry of Oil and Gas Industry of the former USSR; about 10,000 of these wells are self-outflowing. Due to the deficit of budget financing most of the wells were temporarily conserved.
Temporary conservation was performed at different stages of oil deposits research and development. Temporarily conserved wells include: a) wells laid up at the stage of drilling; b) productive wells laid up for future commercial oil extraction; c) productive wells in the state of emergency.
The greatest hazard is presented by the wells in the state of emergency where liberation of gases including hydrogen sulfide and other petroleum products is observed.
Some productive wells are also unsafe, especially those under pressure and conserved in anticipation of further extraction; conservation period for such wells has expired long ago (exceeds 15-20 years). In many of such wells, boring casing is worn out due to exposure to corrosive agents and at any moment the wells can cause immense emergency damaging of the environment. A special danger is presented by the wells in the area of the Caspian Sea flooding. In the past prospecting and development of oil fields at the shore of the Caspian Sea were performed without due consideration of the possibilities for inundation and underfooding with sea waters. Conservation and abandonment of oil field facilities and some oil wells were performed without due isolation from the impact of the corrosive sea water and glacial processes. At present, the technical condition of previously conserved wells requires their liquidation.
According to available data, there are at present 38 oil fields and 39 oil-and-gas structures in the zone of flooding caused by the Caspian Sea; among them 9 oil fields and 15 structures are located in Mangystau oblast (according to information presented by Mangystau Territorial Oblast Department of Environmental Protection and Mangystau Oblast Authorities for Environmental Resources and Nature Use Regulation).
By present about 400 wells are located in the zones of flooding and underflooding by the Caspian Sea in Atyrau and Mangystau oblasts of Western Kazakhstan; 160 of them are in possession of oil field users and 240 wells are beyond the contract territories.
According to the data for March 2008 (local newspaper “Aktau Business” No 12(132) from March 23, 2008 and others), 23 of the wells in Mangystau oblast located in the zone of inundation and underfooding with the Caspian Sea are in emergency state.
According to the data available by June 2003, three oil wells in Atyrau oblast leaked causing formation of oil patches/spots up to a kilometer lengthwise and 20-30 meters widthwise. In spite of the concerns declared and understanding of the urgent need in finding a radical solution of this problem, very few wells are under liquidation at present. A Kazakhstani newspaper “Novoye Pokoleniye” from 21.04.2004 reported the facts of oil leakage and described environmental problems with underflooded wells: By present in Mangystau oblast no one emergency well (flooded or underflooded) has been eliminated.
Territorial natural resources authorities hold tenders with the purpose to reveal such wells and work out measures/procedures aimed at their liquidation. One of the most dramatic problems in the course of flowing-out well liquidation is the depth of water which varies from 0 (in this case a profound layer of silt creates problems) to three meters. Such water depth complicates the application of traditional equipment designed for well liquidation.
A shortcoming of those works that are performed there is low reliability. Piping is not removed from the wells; well mouths are sealed with cement preventing oil spills into the sea. Still, if in the well sealed with metal and cement was formed a channel for oil spills (during 20 – 40 years), then construction of a similar barrier (which may cost ~ $1,000,000 USD) would prevent the spills for the next 20 – 40 years only. So, such periodical works are too expensive for the budget of the country.
Most of the wells subjected to liquidation were previously located on dry land. The liquidation technology did not ensure oil spillage prevention in case of well flooding. Quality of materials used in well liquidations does not correspond to the requirements to offshore wells. A significant amount of wells is damaged by corrosion, ice drifts and corrosive materials present in the boreholes (those are mainly harmful sulfide compounds, hydrogen sulfide H2S) and carbon dioxide.
Oil spillages affect dramatically the state of the Caspian Sea environment. As it was mentioned, different authors argue different volumes of oil escaping from leaky wells. In spite of difference in assessments, it is obvious that the wells in the zone of flooding represent a serious threat to the Caspian Sea environment. One of the results of harmful effects is degradation of vegetation and other forms of life reflected in the reports of state authorities for nature preservation and of non-governmental environmental institutions that have analyzed the situation.
Well abandonment in the zone of flooding is accompanied by the following problems:
- There is no any regulation on abandonment of such wells to take into consideration the specifics of works and hostility of the environment of the well after expiration of a certain period of time. Kazakhstan does not have any experience in such works
- Wells can be covered with a water layer of various depth
- Utilization of conventional drilling rigs, methods of their transportation and mounting-dismantling presents certain difficulties
- Most wells were drilled 20-25 years ago and it is very difficult to evaluate their present technical condition due to unavailability of complete data
- Technologies of well abandonment did not take into consideration at that time the measures on prevention of oil spillage into water
- Corrosion of the above-ground part of collars of wells by sea water
- Possible deformation of a collar by ice drifts
- Difficulties of access to the well collar
- Difficulties in finding the necessary information on the well in archives.
With the purpose to assure analysis of perse information to be obtained during the works, it is planned to develop a project based on modern geoinformation technologies using Geographical Information Sysytem (GIS) ArcGIS. GIS and its geographical approach to obtaining, storage, processing, analysis, simulations, and representation of information on studied objects provides unique opportunities for consideration of the complete set of factors and will allow us to make our knowledge about an object more available and visual for scientists, designers, managers, and technical specialists. Initially, GIS-project will be developed within ArcGIS environment and it will be later published to make it available for use with a freeware ArcReader with easy user-friendly interface.
Highly professional personnel in the Companies «AstanA N-Tech», “Mangystau-Monitoring” Ltd. and DSE “Center for physical and chemical methods of analysis” will allow to solve the above mentioned problems. At the “Center for physical and chemical methods of analysis” with the assistance of international organizations such as ISTC was developed advanced equipment and methods for determination of radionuclide and element composition in environmental objects. Instrumental, chemical and radiochemical methods certified and attested by State standardization authorities Gosstandard of RK have been developed and are successfully applied in environmental studies. The Company “Mangystau-Monitoring” disposes a staff of highly professional and skilled specialists experienced in abandonment of wells and sources of pollution along the Caspian Sea coastline. The Companies «AstanA N-Tech», “Mangystau-Monitoring” and the “Center for physical and chemical methods of analysis” keep State licenses for engineering and ecologic research at the territory of the Republic of Kazakhstan and for abandonment of underflooded and inundated oil wells. The «AstanA N-Tech» Company has got in 2007 from the Ministry of Education and Science of the Republic of Kazakhstan a State Certificate for scientific, applied and environmental studies.
In the implementation of the planned works participate highly professional specialists – physicists, geophysiscists, chemists, engineers and technical personnel with significant experience in the field of nuclear physical, elemental and radionuclide methods of analysis, programmers specialized in creating and analyzing databases, modeling, geology and geophysics.
Expected Results and Their Application.
There will be performed over-all environmental and technical works on evaluation of technical state of flooded and drowned wells and assessed environmental impacts of these objects. Classification of wells will be carried out and for each type recommendations on abandonment of wells will be elaborated taking into consideration international experience in this field as well as recommendations concerning priorities in implementation of recommended works.
Studied wells will be classified according to the danger they represent for the environment and the Caspian Sea. The objects of studies can be pided into two groups. The first group of wells is represented by wells really hazardous for the Caspian Sea and environment. At present in comparison with the period of wells drilling the degree of their flooding and emergency is higher. At the same time it is necessary to take into consideration quantitative data on rates of yield obtained during their testing and accurately evaluate risks for accidents (especially in case of wild flowing) and risks of large oil amounts penetration into the basin of the Caspian Sea. Such accidents can result dramatically on fauna and flora of the Caspian Sea. The second group of wells is represented by wells which do not impose a real threat for the Caspian Sea, but negatively affect environment. These wells were surrounded after drilling with protective dams (and motor roads) preventing the spread of positive setups onto the territory of the oil field and virtually exclude the possibility of oil penetration into the waters of the Caspian Sea. Rates of yield for such wells demonstrate very low values (up to 1.5 m3/sec) and even in case of emergency (up to wild flowing) it is possible to perform their localization and abandonment in a short time.
There will be determined contamination of soils and grounds due to their flooding with oil and oil field (stratal) waters. There will also be performed comparative of soil contamination with heavy metals, chemical components and arsenic (for soils of various physical and chemical properties) with current standards regulating their maximal permissible concentrations (MPC) in soils and water. “Methodical Instructions on Revealing Degraded and Contaminated Lands” will be used to estimate quantitatively the degree of soils contamination with oil and oil products. It is also planned to determine salinity of stratal waters and soils as well as the depth of penetration of oil contaminants (polluted thickness) into soils.
Technical state of at-conservation exploratory wells in the zone of underflooding and inundation by the Caspian Sea will be evaluated. Sequence for liquidation of oil-prospecting wells in the zone of underflooding and inundation by the Caspian Sea will be determined.
There will be developed recommendations and inpidual plans for liquidation of specific wells that are in different technical conditions. It is planned to prepare recommendations on choice of rehabilitation technologies, abandonment measures and their implementation.
In the project work plan the role of each participating Institutions as well as the interrelation of their activities are clearly defined.
In the framework of ISTC project K-1354d (Project Development Grant) the detailed work plan was developed and agreed with project collaborators during personally meetings, joint scientific seminars and consultations. During the project it is planned to keep a constant coordination and partnership with all the five foreign collaborators. In the close contact with collaborators our research will be planned and work results discussed. The important elements of our scientists’ integration into the world scientific community will be their joint attendance with the collaborators at scientific seminars including participation in the international conferences in Kazakhstan and abroad.
The International Science and Technology Center (ISTC) is an intergovernmental organization connecting scientists from Kazakhstan, Armenia, Tajikistan, Kyrgyzstan, and Georgia with their peers and research organizations in the EU, Japan, Republic of Korea, Norway and the United States.
ISTC facilitates international science projects and assists the global scientific and business community to source and engage with CIS and Georgian institutes that develop or possess an excellence of scientific know-how.