ISSN:
2181-3906
2023
International scientific journal
«MODERN SCIENCE АND RESEARCH»
VOLUME 2 / ISSUE 11 / UIF:8.2 / MODERNSCIENCE.UZ
1027
REQUIREMENTS FOR WELL DESIGNS AT THE UMID FIELD
Avlayarova N.M.
Karshi Engineering and Economic Institute, Karshi, Uzbekistan.
https://doi.org/10.5281/zenodo.10252773
Abstract.
The design of a well depends on the objectives, geological conditions, depth,
drilling technique, field development method and other factors. In the process of drilling wells at
the Umid field, complications are possible, such as the presence of a thick chemogenic strata of
the Kimmeridgian Titon, which creates certain difficulties when drilling wells (coagulation of the
drilling fluid, fluidity of salts, and in some cases, mineral deposits). This article discusses possible
complications during the drilling process and requirements for well designs at the Umid field.
Key words:
Field, massive, gas deposit, oil rim, gas cap, well, structure, brine-bearing
zone, brine-safe zone.
ТРЕБОВАНИЯ К ПРОЕКТАМ СКВАЖИН НА МЕСТОРОЖДЕНИИ УМИД
Аннотация.
Конструкция скважины зависит от целей, геологических условий,
глубины, техники бурения, способа разработки месторождения и других факторов. В
процессе бурения скважин на месторождении Умид возможны осложнения, такие как
наличие мощной хемогенной толщи кимериджского титона, что создает определенные
трудности при бурении скважин (коагуляция бурового раствора, текучесть солей и в
некоторых случаи, месторождения полезных ископаемых). В данной статье
рассматриваются возможные осложнения в процессе бурения и требования к
конструкциям скважин на месторождении Умид.
Ключевые слова:
Месторождение, массив, газовая залежь, нефтяная оторочка,
газовая шапка, скважина, строение, рапоносная зона, рапобезопасная зона.
Disturbances in the continuity of the technological process of construction (drilling for
testing) of a well, subject to compliance with the technical design and rules of work, caused by
phenomena of a mining and geological nature, such as absorption, oil and gas shows, emissions,
landslides, jelly-like workings, bore curvatures, open flowing, as well as the consequences of
natural disasters disasters are complications. Most of them are the result of a violation of
technological discipline (technology), some are explained by insufficient knowledge of geological
and physical conditions, especially in exploratory drilling, and a lack of understanding of the root
causes of the phenomena that precede the complication.
During the process of drilling wells at the Umid field, the following complications are
possible:
- screes and collapses of borehole walls in Paleogene deposits;
- absorption of washing liquid with loss of circulation in the Bukhara layers of the
Paleocene;
- partial absorption of flushing fluid, screes and collapses of well walls, cavern formation,
trenching in chalk deposits;
- the presence of a thick chemogenic strata of the Kimmeridgian Titon, which creates
certain difficulties when drilling wells (coagulation of drilling fluid, fluidity of salts, in some cases,
mineralization);
ISSN:
2181-3906
2023
International scientific journal
«MODERN SCIENCE АND RESEARCH»
VOLUME 2 / ISSUE 11 / UIF:8.2 / MODERNSCIENCE.UZ
1028
- absorption of washing liquid with loss of circulation in the callovian-oxfordian deposits
of the Upper Jurassic;
- oil and gas water shows in the callovian-oxfordian productive horizons.
The design of wells must meet the following requirements:
- ensure mechanical stability of the wellbore walls and reliable separation of all (oil, gas,
water) layers from each other, free access to the bottom of the wells for lowering equipment, and
prevention of rock collapse in the wellbore;
- effective and reliable connection of the well bottom with the productive (oil or gas)
formation;
- the possibility of sealing the wellhead and ensuring the direction of the extracted product
into the system for collecting, preparing and transporting oil and gas or injecting an impact agent
into the formation;
- the possibility of carrying out research work in wells, as well as various geological,
technical and maintenance work.
Administratively, the Umid field is located within the Mirishkor district of the Kashkadarya
region of the Republic of Uzbekistan. There are no populated areas on the territory of the deposit.
The nearest settlements are: the city of Karaul-Bazar (65 km to the north), the city of Bukhara -
the regional center (125 km to the east) and the city of Mubarek (55 km to the northeast). The
BGO – Tashkent-Bishkek – Almaty gas pipeline runs 37 km to the north. The North Urtabulak oil
field is located 10 km to the south.
The Umid deposit is located within the southeastern part of the Chardzhou tectonic stage.
The main tectonic elements of the region under consideration are the Dengizkul and Ispanly-
Chandyr uplifts. These two uplifts are separated by the eastern end of the Karakul (Kushab) trough.
The Umid deposit is located in the junction zone of the Dengizkul uplift with the Kushab trough.
The Umid field is a massive gas reservoir with an underlying oil rim confined to the upper
part of the reef massif. The total thickness of the oil rim is 10 m – 12 m, the gas cap – 110 m – 125
m. The initial positions of the GNK and VNK are, respectively, minus 2322 m and minus 2333 m
In the sulfate-halogen deposits of the Umid field there are brine-hazardous areas, the
presence of brine-bearing deposits is confirmed by the results of drilling wells No. 7, No. 81. In
protocol No. 6 dated July 17, 1996, it was stated that the boundaries of the zones of brine-hazardous
areas were established on the basis of CDP seismic surveys.
One of the severe types of complications when drilling wells in oil and gas provinces in
the presence of thick salt-bearing strata are brine manifestations, accompanied by the outflow of
natural brines in a wide range of flow rates. As a rule, mineral accumulation zones have abnormally
high reservoir pressures, reaching reservoir pressure gradients of up to 0.020 MPa/m or more.
Manifestations of highly mineralized waters from salt-bearing strata were encountered
when drilling wells in the regions of the Dnieper-Donets Depression (DDV) in Ukraine and Central
Asia. In Russia, this type of complication is widely represented in the Caspian basin (North
Caucasus, Astrakhan, Volgograd, Saratov, Orenburg regions), as well as in a number of regions of
Eastern Siberia. Abroad, this type of complication has been widely noted when drilling wells in
the Mississippi Basin of the USA and a number of other regions.
ISSN:
2181-3906
2023
International scientific journal
«MODERN SCIENCE АND RESEARCH»
VOLUME 2 / ISSUE 11 / UIF:8.2 / MODERNSCIENCE.UZ
1029
Thermobaric conditions of mineralization zones are associated with the depths of their
occurrence and temperature gradients in the regions.
In Central Asia, at depths of chemogenic deposits up to 3000 m, brine temperatures at the
well exit reach 80 - 110°C with reservoir pressure gradients reaching 0.0235 MPa/m and flow rates
from several tens to several thousand cubic meters per day, which additionally led to the
precipitation of salts in the wellbores and significantly complicated the work to eliminate
complications.
The appearance of brine is a very unpleasant phenomenon, which is one of the serious
complications when drilling wells in oil and gas provinces in the presence of powerful salts. Rapa
is a very saturated salt solution with a gel-like consistency. It is found not only in surface
reservoirs, but also deep in the bowels of the earth, when layers of rock salt are in direct contact
with layers of water-saturated rocks. Mineral manifestations greatly complicate the drilling
process, since the drilling tool slips and goes off the trajectory.
A distinctive feature of the geological structure of the Umid field is the presence of poorly
developed ore-bearing zones in the chemogenic sequence of the Kimmeridgian Tithonian of the
Upper Jurassic. This circumstance dictates a differentiated approach to the choice of well design.
The presence of brine zones predetermines the use of well designs that allow separate penetration
of chalk deposits and chemogenic strata, while in wells without brine, drilling of salt-anhydrite
strata is possible without prior covering of chalk deposits.
Tables 1 – 2 show well designs for both drilling zones with a design depth of 2650 m.
REFERENCES
1. V.I. Kudinov “Fundamentals of oil and gas production.” M.: Izhevsk. 2005.
2. Clarification of the geological model of the Umid field with recalculation of oil reserves:
Research report / UzbekNIPIneftegaz Responsible executor Dmitriev Yu.P. etc. - Tashkent,
1996.
3. Umid field development project. Research report/JSC UzLITIneftgaz; Responsible
executive Posevich A.G. etc. – Tashkent, 2010.
4. Avlayarova N. M., Makhmudova Sh. Requirements for well designs, technologies and
drilling operations at the Umid oil and gas condensate field // Science and Technology.
World Research. – 2020. – C. 13-16.
ISSN:
2181-3906
2023
International scientific journal
«MODERN SCIENCE АND RESEARCH»
VOLUME 2 / ISSUE 11 / UIF:8.2 / MODERNSCIENCE.UZ
1030
ISSN:
2181-3906
2023
International scientific journal
«MODERN SCIENCE АND RESEARCH»
VOLUME 2 / ISSUE 11 / UIF:8.2 / MODERNSCIENCE.UZ
1031
