CC BY
5
UDC 608
Deryaev A.R.
Candidate of Technical Sciences, Senior Researcher, Scientific Research Institute of Natural Gas of the State Concern Turkmengas",
Ashgabat, Turkmenistan
THE MAIN PROSPECTS OF DEVELOPMENT AND ENGINEERING PLANNING OF DRILLING
OPERATIONS AND HORIZONTAL DRILLING
Abstract
A horizontal wellbore in the production horizon helps to extract oil from the reservoir more evenly and reduces the tendency to form depressions characteristic of vertical wellbore, where the underlying water or gas from the lawn part above the oil reservoir zone moves intensively to the wellbore.
Keywords
Project, trajectory, inclination angle, azimuth, well design, completion, drifting.
The need for further increase (build-up) of oil and gas, as well as an increase in their production, has led to a significant qualitative increase in drilling operations. Hence, improving the technique and technology of drilling (deep), significantly increasing the productivity of drilling operations and reducing their cost is a serious task. Geological, geophysical and technical data are of great importance in principle to improve the accuracy and reliability of the description of the section opened by the well and the management of the drilling process.
The need for further improvement of drilling is also dictated by the complexity of the geological and technical tasks being solved:
1. In all likelihood, the scheme of deep mechanical drilling will remain for many years to come.
2. To increase drilling speeds, it is necessary in the total volume of drilling operations (hydraulic and electric downhole motors).
3. There are many reasons to assume an increase in the volume of directional drilling from the horizontal sections of the trunks under the productive formation.
The experience of working in different regions of the world demonstrates the success of horizontal well drilling technology.
A review of the works reviewed in various parts of the world shows the high prospects of horizontal drilling in terms of increasing production and solving well completion. As practical experience shows, horizontal drilling is becoming an important area of technical progress in terms of increasing production and solving problems of well completion. In the near future, the oil and gas industry will consider horizontal drilling as a means of increasing the coefficient of oil collection with thin productive zones or reserves of economic feasibility of production (development).
Technical and technological innovations are already widely used in horizontal drilling. New technologies based on directional drilling in practice can effectively extract reserves of carbohydrate resources on an industrial scale of a well being drilled at a given field.
The tasks set for the oil industry to increase oil production can be fulfilled only if the speeds of well wiring and horizontal drilling are further increased. In order to ensure the appropriate rate of commissioning of wells with a continuous development system, while a significant role is played, the organization of drilling operations should be at a high level due to the tight deadlines for drilling the area.
There are two possible solutions here:
- Or increase simultaneously operating pairs of operating drilling rigs.
- Or, with a smaller number of them, increase the cyclical speeds, which is essentially what it is necessary to strive for when drilling individual wells and all wells in general, in addition, specific capital investments decrease.
It should be noted that oil reservoirs are developed by a system of production wells located either side by side or in the form of a uniform geometric grid (triangular or square).
The placement of wells nearby is used in the development of oil reservoirs with high productivity and good permeability, as well as in conditions when the oil deposit is subject to a stratigraphic trap. In all other cases, wells are placed on a geometric grid. The distance between the wells (with a uniform grid of wells) and between the rows are of paramount importance [1].
The choice of a rational distance between production wells is based on the laws of underground hydrodynamics, taking into account the physico-geological features of the productive horizon. When choosing the distance between wells, economic considerations must also be taken into account, since the total number of wells intended for drilling oil deposits depends on the distance. When designing the development of a field, it is necessary to have several options for the placement of wells (providing for different distances between them) and comparing them to choose the most profitable option.
The sequence of the location of the borehole sections (vertical, rectilinear, inclined, horizontal, set and decrease the angle of inclination) is determined by the configuration. The profile configuration of horizontal wells should be selected taking into account the specific conditions of the field. The sections of the profile should be arranged in such a sequence that they would best meet the conditions of drilling this field and well operation.
When choosing a profile, a horizontal well must be taken into account.
1. Type of deposit - in the case of a multi-layer deposit, the well opens several productive horizons at the same time, without disturbing the grid of their development.
2. The angle of occurrence of the productive reservoir.
3. Type of productive formation rocks - in unstable rocks, the well should open the productive formation vertically, and stable rocks allow you to open the productive formation at any angle of inclination.
The selected configuration of the horizontal (inclined) well profile should provide the best conditions for oil production with the method of operation adopted in the rational system of field development.
The importance of oil and gas in the national economy is increasing every year. Further increases in oil production volumes in the near future will be mainly due not to the commissioning of new fields, but to an increase in oil recovery at fields at a late stage of development. In this direction, it is especially important to develop new methods and technologies, since existing methods give low oil recovery coefficients («30^50%).
In recent years, there has been a tendency to increase the depths of oil deposits being drilled, as well as the depths of horizons promising for prospecting and exploration.
As drilling wells deepen, the impact of hydrodynamic, physico-chemical and mechanical processes occurring in the drilling fluid on the general condition of the well system - rocks - also increases. As a result, the frequency and degree of complications usually increase with depth, and the cost of money and time to combat them increases. To avoid this, it is necessary to rebuild drilling technologies, change them in accordance with the increasingly complex conditions of well wiring.
The main difference between the technology of wiring conventional and deep wells is the expensive and lengthy preparation for drilling deep and ultra-deep wells. Moreover, the costs are associated not only with the acquisition of the necessary ground-based deep equipment, but with a thorough study of drilling at great depths.
The development of a new geological and technical discipline - reservoir pressure management during drilling - and its implementation will contribute to the technical re-equipment and organizational restructuring of domestic deep drilling on a national basis. This will require very close creative interaction of scientists and production workers of various profiles: geologists, geophysicists, drillers and other specialists.
Literature
1. Х. Гулатаров, Деряев А.Р., Еседулаев Р.Э. Особенности технологии бурения горизонтальных скважин способом электробурения, (Монография), Наука, Ашгабат 2019, Стр. 276-301.
© Deryaev A.R., 2022
