The Mamontovskoye field has been in commercial production since the spring of 1970. The main productive horizon contains about 80 percent of the oil reserves. Horizons with low productivity have a complex structure and wide oil-water areas. Their development is planned after the development of the main reservoir. The field is drilled according to a three-row system and refers to the type of falling oil production.
Where is the Mamontovskoye field located?
Administratively, the field is located in the Nefteyugansk region of the Khanty-Mansiysk Autonomous Okrug (Tyumen Oblast). Geographically, the basin belongs to the watershed of the Bolshoi and Maly Balyk (rivers). According to geomorphology, it is a gentle, slightly dissected plain. The main rivers are accompanied by a large number of tributaries, a large area is occupied by wetlands.
Significant interfluve massifs are covered with mixed forests with predominance of conifers. The climatic conditions of the region are sharply continental type. In winter, the temperature reaches –50 degrees, in the summer it rises to +35.
Historical facts
The Mamontovskoye field was discovered in 1965 (development began in 1970) and is one of the largest fields in Western Siberia. In terms of maximum oil production, it ranks second after Samotlor . During operation, four times more oil was recovered from the bowels than in the Variegansky, Talinsky , Sutorminsky and Lyantorsky basins combined.
The history of development of the Mamontovskoye field is determined by strategically correctly conducted developments. The main focus is the continuous improvement of the production system , starting from low-intensity structures, in order to optimally extract all reserves and stabilize oil production.
Compared to other fields in Western Siberia, production at the Mamont horizons exceeded the figures almost doubled, amounting to 70 percent. It surpasses all other basins in the average oil production rate (26 tons per day as of 1990).
Features of well designs
Structurally, the wells of the Mamontovskoye oil field represent a typical configuration for Western Siberia. Their features depend on the expected geological conditions of the territories being drilled, the depth of the raw material mass, and the subjective parameters of the layers to be processed. The design used must guarantee stable protection of the subsoil, the possibility of using a specific type of drilling, and ensure the planned speed indicators for sinking and conducting scientific and research work in an open or cased hole.
To prevent erosion of the wellhead and to ensure stable fastening of the upper interval, the direction is lowered to a depth of 30 meters (diameter - 323.9 m). The element is cemented to the mouth. Also, a special conductor with a diameter of 245 mm, which is cemented to the mouth, goes down to 680 meters. It serves to strengthen the upper unstable cutting intervals, to protect aquifers from pollution. In addition, blowout devices are installed with his help, as well as casing suspension. It, in turn, descends to a depth of 2.67 km, has a diameter of 146 mm, and also cements to the mouth.
Start of production drilling
The first test attempts to develop the Mamontovskoye field began in the summer of 1968. Production drilling was launched according to the technological scheme developed by VNII (1967) . According to this documentation, one BS 10 horizon should be introduced into development. In parallel, it was planned to develop AC 4 and AC 5 , and the BS 8 layer was considered as a returnable object. The first to be commissioned were five producing wells.
Two months after their commissioning, flooding began at the Mamontovskoye field, the main task of which was to maintain pressure in the developed reservoirs. All wells operate on the principle of a fountain.
Since 1978, the project AC 4 -5-6 comes into force, involving the active development of formations A4 and A5. The documentation for the development of reservoirs was compiled by SibNIINP . The same institution in 1981 is developing a technological scheme for the BS 8 formation. As a result , six autonomous developing facilities are allocated.
Development
Mamontovskoye oil and gas field is characterized by high drilling rates. In the first half of the 80s of the last century, production drilling covered over a million linear meters. In addition, up to 400 new wells are commissioned each year. The average production rate with anhydrous production is up to 117 tons of oil from one well.
Already in the first year of operation of the Mamontovskoye oil field, 42 oil and 6 injection wells operate. The extracted black gold is more than 485 thousand tons per year with the injection of 149 thousand cubic meters. In the following years, the production rate continues to grow. In 1986, the maximum indicator was reached, which amounted to 35 million 166 thousand tons. The rate of selection parameter as a percentage amounted to 6.3% of the initial recoverable resources.
Mamontovskoye field: oil and gas potential
The field in 1987 overcame a fifty-percent flood line. In this regard, annual oil production began to decline. At the same time, the amount of produced fluid increased. Another factor in the decline was the reduction in production drilling. By the mid-80s of the 20th century, the field was actually completely drilled. Further work was carried out on the outskirts of the basin, as well as work was carried out to seal the grid of wells. The field began to urgently need to develop new project documentation , with the preparation of which SibNIIIP was not particularly in a hurry.
Further story
The volume of fluid and its production continued to increase until 1990. The maximum level of production amounted to 92 million 887 thousand tons. The same year was marked by the presence of the maximum existing fund of oil rigs. Then, due to the growth of idle wells, a drop in water volume is observed. From 1990 to 1995, the rate of decline of the current fund was over 6 percent. As a result, a decrease in liquid production resulted in a decrease in oil production.
The maximum rate of injection was also observed in 1990. It amounted to more than 119 million cubic meters of water while servicing 943 injection wells. During 1995, more than 8.5 million tons of oil were produced. The annual selection rate was about 1.5 percent of the initial ones, and the same indicator for selection from current stocks varied in the range of 6 percent. With a water content of more than 80 percent, the average production rate of one well is 13.7 tons of oil per day. In the same year, a little more than 34 thousand meters of rock were drilled by production drilling.
Summary analysis
The use of hydrochloric acid treatment and waterflooding at the Mamontovskoye field has become one of the decisive factors guaranteeing the active development and achievement of high production rates in the region with the provision of favorable economic data.
In the developed areas, the models of intra-contour flooding are widely used, which is the cutting of deposits into strips of different widths. In addition, pilot industrial research and work is underway aimed at using block-square flooding. Some fields have successfully used barrier systems suitable for areas with extensive sub-gas zones.
It is worth noting that the development of fields in Western Siberia, carried out for more than 30 years, allowed to carry out a huge amount of work not only on the development of oil production, but also on the introduction of effective water flooding systems that allow rational use of available resources. In this vein, it is worth noting the Mamontovskoye field, which in better times produced an order of magnitude more production than the surrounding pools combined.