scholarly journals EXPERIENCE OF OILFIELD DEVELOPMENT IN PERM KRAI USING HORIZONTAL WELLS

Author(s):  
Roman A. Zaitcev ◽  
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Aleksei V. Raspopov ◽  

Hydrocarbon reservoir engineering has a top priority to achieve the highest possible value of the cost-effective oilrecovery factor. Structural deterioration of residual oil reserves and inevitable development of hard-to-recover reservesrequire new effective technologies and engineering solutions. Today, there is a tendency to replace the standard sizewell drilling technologies (including vertical, directional, horizontal, multilateral wells) and standard size dualcompletion equipment usage by slim-hole drilling technologies. In Perm Krai fields, more than 385 horizontal wellshave been drilled, while 3.4 % of them, i.e. 13 wells, have a small diameter. The conducted well operation analysisshows that the effectiveness of the horizontal well operations in a number of instances is significantly lower than thepotential one. This leads to a deteriorated economic performance of reservoir developments, and, eventually, to assetvalue reductions. Perhaps, the main reason of low effectiveness of the horizontal well operations lies is an insufficientunderstanding of geological and physical conditions of their successful operations. It has become obvious that drillinghorizontal wells in reservoirs with high compartmentalization, low net oil thickness, and decreased hydrodynamicconnectivity to the edge water zone offer a low level of performance. Productivity tends to decrease to average outputvalues of directional wells. Therefore, the problem of choosing a well design and its direction in specific geological andphysical conditions is highly relevant.

Author(s):  
Bruce Misstear

The key well design issues considered in this paper are the length of the intake section; the hydraulic efficiency of the well; the length of grouted upper casing for wells in fractured rock aquifers and the potential trade-off between well yield and security against pollution; and the economics of well design. For wells in thick, relatively uniform unconsolidated aquifers, the well depth and screen length can be estimated using a simple discharge-drawdown relationship. This approach can help avoid constructing unnecessarily deep wells if alternative guidance to screen the bottom third of the aquifer was followed in such situations. Hydraulic efficiency is an important consideration in well design: the paper highlights that whereas screen entrance velocity has been a topic of much discussion in the literature, well upflow velocity has received less attention, but can be an important contributor to well losses in small diameter screens. In fractured hard rock aquifers, there may be a compromise required in well design between maximising well yield by exploiting shallow fracture zones whilst also providing adequate sanitary protection to the well by installing an upper grouted casing. Recent data from Ireland on the distribution of hydraulic conductivity with depth in poorly productive fractured rock aquifers are used to calculate the reduction in well yield that would result from increasing the length of the grouted upper well casing. Economic aspects of well design are especially important where there are a large number of wells to be drilled and/or where wells are required in poor rural communities in developing countries. The principles of cost-effective boreholes for developing countries are summarised, noting the opportunities for small-diameter shallow wells constructed with inexpensive manual or lightweight mechanical drilling rigs.


2016 ◽  
Author(s):  
Emmanuel Soquar ◽  
Chris van der Westhuyzen

ABSTRACT Onshore exploration – both oil and gas and geothermal – typically involves the mobilisation of full sized conventional rigs. The support package includes back up and auxiliary parts, capable of drilling and fully evaluating deep large diameter conventional holes. In early stage exploration programs conducted in remote and frontier locations, the operating costs can approximate those of an offshore operation. This standard approach may be an unnecessary expense and lessons can be learned from the mining industry, which has been operating in a lower cost environment in frontier locations for over 125 years. A slim well approach is adopted not just to the well design but to team size, civil works, evaluation requirements and logistics. A smaller rig capable of drilling slim wells to the desired terminal depth (of up to 4,000 m), with complete logging and core sampling, can provide exploration companies with a cost effective solution.


Author(s):  
Wesley McCall ◽  
Thomas M. Christy ◽  
James J. Butler

Direct push (DP) methods provide a cost-effective alternative to conventional rotary drilling for investigations in unconsolidated formations. DP methods are commonly used for sampling soil gas, soil and groundwater; installing small-diameter monitoring wells; electrical logging; cone penetration testing; and standard penetration tests. Most recently, DP methods and equipment for vertical profiling of formation hydraulic conductivity (K) have been developed. Knowledge of the vertical and lateral variations in K is integral to understanding contaminant migration and, therefore, essential to designing an adequate and effective remediation system. DP-installed groundwater sampling tools may be used to access discrete intervals of the formation to conduct pneumatic slug tests. A small-diameter (38mm OD) single tube protected screen device allows the investigator to access one depth interval per advancement. Alternatively, a larger diameter (54mm OD) dual-tube groundwater profiling system may be used to access the formation at multiple depths during a single advancement. Once the appropriate tool is installed and developed, a pneumatic manifold is installed on the top of the DP rod string. The manifold includes the valving, regulator, and pressure gauge needed for pneumatic slug testing. A small-diameter pressure transducer is inserted via an airtight fitting in the pneumatic manifold, and a data-acquisition device connected to a laptop computer enables the slug test data to be acquired, displayed, and saved for analysis. Conventional data analysis methods can then be used to calculate the K value from the test data. A simple correction for tube diameter has been developed for slug tests in highly permeable aquifers. The pneumatic slug testing technique combined with DP-installed tools provides a cost-effective method for vertical profiling of K. Field comparison of this method to slug tests in conventional monitoring wells verified that this approach provides accurate K values. Use of this new approach can provide data on three-dimensional variations in hydraulic conductivity at a level of detail that has not previously been available. This will improve understanding of contaminant migration and the efficiency and quality of remedial system design, and ultimately, should lead to significant cost reductions.


2020 ◽  
pp. 57-60
Author(s):  
K.I. Mustafaev ◽  
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◽  

The production of residual oil reserves in the fields being in a long-term exploitation is of current interest. The extraction of residual oil in such fields was cost-effective and simple technological process and is always hot topic for researchers. Oil wells become flooded in the course of time. The appearance of water shows in production wells in the field development and operation is basically negative occurrence and requires severe control. Namely for this reason, the studies were oriented, foremost, to the prevention of water shows in production well and the elimination of its complications as well. The paper discusses the ways of reflux efficiency increase during long-term exploitation and at the final stages of development to prevent the irrigation and water use in production wells.


Author(s):  
Shu KONDO ◽  
Daiki YAMAMOTO ◽  
Kamal Prasad Prasad Sharma ◽  
Yazid Yaakob ◽  
Takahiro SAIDA ◽  
...  

Abstract We performed single-walled carbon nanotube (SWCNT) growth on flexible stainless-steel foils by applying alcohol catalytic chemical vapor deposition using an Ir catalyst with an alumina buffer layer. When the alumina thickness was 90 nm, vertically aligned SWCNTs with a thickness of 4.6 m were grown. In addition, Raman results showed that the diameters of most SWCNTs were distributed below 1.1 nm. Compared with conventional chemical vapor deposition growth where Si wafers are used as substrates, this method is more cost effective and easier to extend for mass production of small-diameter SWCNTs.


Georesursy ◽  
2020 ◽  
Vol 22 (3) ◽  
pp. 2-11
Author(s):  
Mikhail A. Fomin ◽  
Rashid M. Saitov

The article presents the results of studying the geological structure of the Bazhenov Formation in the Nadym-Ob interfluve of Western Siberia with the aim of predicting the oil content of this black shale stratum. As a result of interpretation of a wide range of well logging represented by electric, radioactive and acoustic logging, with subsequent matching of these results with paleontological definitions of micro- and macrofauna, the distribution of the Salym, Nizhnevartovsky and Tarkosalinsky types of sections of the Bazhenov Formation was clarified, transitional areas between them were identified. It has been established that the Tarkosalinsky type is more widespread in the western direction than was shown earlier and is also distinguished in the Vengayakhinskaya, Yaraynerskaya and other areas. The Nizhnevartovsky type, on the contrary, has a narrower distribution and stands out directly within the same name arc and to the south by the Variegasky-Tagrinsky megahigh. On the basis of geological, geochemical, geophysical criteria and the results of an inflow test in deep wells, a map of the oil potential prospects of the “classical” sections of the Bazhenov Formation has been compiled. Regional prerequisites (high catagenesis of organic matter, significant modern concentrations of organic carbon, etc.) for the discovery of industrial accumulations of oil in the Bazhenov Formation in the southern regions of the Yamalo-Nenets Autonomous Area are identified. The results of the test for the inflow of the Bazhenov Formation in this area in the 70–90s XX century were analyzed; repeated, interval testing of these deposits using modern methods of stimulation of the inflow is recommended. The necessity of laboratory lithological, petrophysical, geochemical study of the core of the Bazhenov Formation in the southern part of the Yamalo-Nenets Autonomous Area is substantiated with the aim of determining its lithological composition, identifying oil source and oil productive intervals, studying the reservoir structure and the nature of saturation of its void space, developing recommendations for calculating oil reserves and creating technology for its cost-effective production.


2021 ◽  
Author(s):  
Ruslan Fanisovich Gataullin ◽  
Stanislav Evgen’evich Ter-Saakov ◽  
Evgenij Vladimirovich Nikulin ◽  
Dmitriy Pavlovich Stifeev ◽  
Alexey Vyacheslavovich Filatov

Abstract This article describes engineering and technology solutions developed to successfully construct unconventional and unique horizontal well at the field of Eastern Siberia targeted to two isolated formations with an option to shut-off top Botuobinsky horizon after gas breakthrough and produce oil from underlying Ulakhansky bed further on. As oil-water contact in the lower part of Ulakhansky horizon makes fracturing the well inexpedient, multi hole drilling technology was implemented enabling drainage of the reserves that are far from the main borehole. The main objective of this well is to deplete Botuobinsky horizon subsequently shutting it off and continuing to recover petroleum reserves from Ulakhansky pay zone. Constructing such well is cost-effective, as it requires drilling only one intermediate casing interval instead of two. Accumulated experience of drilling and completing multi hole wells was used to ensure successful well construction; also, geological and stratigraphic data as well as possible complications while drilling Botuobunsky and Ulakhansky formations were analyzed in-depth. The following appliances were selected to meet the objective: –Bottom-hole equipment enabling drilling abrasive formations under conditions of high vibrations;–Special line of drill bits to ensure high ROP and successful sidetracking without additional tripping;–RSS with 152.4 mm drill bit. The goal set by the operating company was achieved through multi-faceted approach to performing the task, efficient cooperation of engineering technical services and continuous monitoring of output data while drilling. All that combined delivered the results listed below: –Sidetracks were carried out in an open horizontal hole without cement plugs and additional tripping for drill bit or BHA.–Minimized bottom-hole equipment failures under condition of increased high-frequency vibrations from bit while drilling hard formations due to implementation of modular PDM with data-transmitting channel.–Minimized bottom-hole equipment failures under condition of increased low-frequency vibrations from drill string with Hard Bending due to improved BHA design and optimized drilling parameters selection.–Liner was effectively run to Botuobinsky and Ulakhansky reservoirs with an option to shut-off the former after depletion and gas breakthrough. This well is the first one targeted at two isolated formations in East Siberia.


2021 ◽  
Author(s):  
Yun Thiam Yap ◽  
Avinash Kishore Kumar

Abstract Typically, most of the well abandonment practice is reference to the recognized industry standards i.e. NORSOK, UK Oil & Gas and etc, and this is how the wells abandonment was carried out in the past. These practices however evolved/changed over time with lessons learnt and experiences and turn into a fit for purpose solutions for the Client. The shift in international and local standards and regulations for a robust plug and abandonment approach has placed the need for a better and long lasting permanent P&A methodology. Adhering to the existing industry standards in well abandonment is somehow not practical and not cost effective to be implemented in different part of the well, where there are major differences in local regulations, reservoir conditions, caprock thickness, well design philosophy and etc. The magnitude of abandonment cost increase is not at par with the risk reduction in long term hydrocarbon leakage. A fit for purpose solutions is recommended in closing the gap between cost and risk. Due to the extremely varied well architecture between wells, the approach to permanent abandonment varies depending on casing sizes, presence of packers and no of casings present to the caprock area. On top of that, identifying the highest depth for a placement of cement plug will reduce on the amount of plugs to be placed, saving rig time and operational time. So far, 16 idle wells have since been permanently abandoned with the systematic approach of applying caprock restoration concept and reinstating the poor isolation across caprock areas with cement with the assistance of technology to the likes of perf-wash-cement, and hydro mechanical casing cutter. These wells have successfully been abandoned as per host authority standards. This paper will explore a major local oil company’ approach to decommissioning of wells, in line with local regulations enforced, while ensuring a cost effective approach is applied in line with the available technologies.


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