The Research and Application of Vertical Wells Multilayer Fracturing Technology

2014 ◽  
Vol 670-671 ◽  
pp. 997-1002 ◽  
Author(s):  
Li Wei Zhang ◽  
Li Hua Fan ◽  
Yu Lian Chang

The difficulties in oil mining is increasing and the quality of the remaining oil reduced gradually after Daqing oil field came into the late high water contamination stage. There are several factors that prevent the convention from single layer fracturing technology to multilayer fracturing technology. Firstly, about 20% of fracturing rate could be achieved by elevating the K Series packer 3 times in the 5 fracturing techniques, but the performance of the plastic tube cannot be guaranteed. Secondly, the fracturing success rate is not guaranteed if Y series are elevated 4 times to complete the 5 layer fracturing, besides consistent intervals between the five layers must be maintained, which is very difficult. To further enhance the vertical well fracturing multilayer capability, we carry out multi-layered vertical well fracturing technology research, and have achieved good results in the field application.

2020 ◽  
pp. 74-80
Author(s):  
V. V. Saltykov ◽  
Yu. S. Makovsky ◽  
M. M. Mansurova

A complex of special equipment is required for the construction of high-tech wells. The basis of modern time efficient, precise and safe drilling is rotary steerable systems (RSS). For the past five years, rotary steerable systems have been using in Russia as a technical and technological solution to reduce accidents and to improve the quality of well construction with large vertical deviations of the extended drilling radius. These systems allow drilling to be oriented along the entire length of the well. Rotary steerable systems allows drilling both perfectly vertical wells with a deviation angle of not more than 0,2°, and horizontal wells more than 2 000 metres long. Implementation of rotary steerable systems allows building wells with extremely extended reach and conducting wells in 1–2 metres thick reservoirs with precision. In 2016, OktoGeo LLC carried out pilot well program with APS Technology's 172 mm RSS (with power section) at an oil field in the territory of KhantyMansiysk Autonomous Okrug — Ugra. All the rotary steerable system positioning programs were completed based on the results of that work and results of drilling 2 205 metres long directional well.


Agronomy ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1283
Author(s):  
Vasileios Ziogas ◽  
Georgia Tanou ◽  
Giasemi Morianou ◽  
Nektarios Kourgialas

Among the various abiotic stresses, drought is the major factor limiting crop productivity worldwide. Citrus has been recognized as a fruit tree crop group of great importance to the global agricultural sector since there are 140 citrus-producing countries worldwide. The majority of citrus-producing areas are subjected to dry and hot summer weather, limited availability of water resources with parallel low-quality irrigation water due to increased salinity regimes. Citrus trees are generally classified as “salt-intolerant” with high water needs, especially during summer. Water scarcity negatively affects plant growth and impairs cell metabolism, affecting the overall tree growth and the quality of produced fruit. Key factors that overall attempt to sustain and withstand the negative effect of salinity and drought stress are the extensive use of rootstocks in citriculture as well as the appropriate agronomical and irrigation practices applied. This review paper emphasizes and summarizes the crucial role of the above factors in the sustainability of citriculture.


2021 ◽  
pp. 014459872199465
Author(s):  
Yuhui Zhou ◽  
Sheng Lei ◽  
Xuebiao Du ◽  
Shichang Ju ◽  
Wei Li

Carbonate reservoirs are highly heterogeneous. During waterflooding stage, the channeling phenomenon of displacing fluid in high-permeability layers easily leads to early water breakthrough and high water-cut with low recovery rate. To quantitatively characterize the inter-well connectivity parameters (including conductivity and connected volume), we developed an inter-well connectivity model based on the principle of inter-well connectivity and the geological data and development performance of carbonate reservoirs. Thus, the planar water injection allocation factors and water injection utilization rate of different layers can be obtained. In addition, when the proposed model is integrated with automatic history matching method and production optimization algorithm, the real-time oil and water production can be optimized and predicted. Field application demonstrates that adjusting injection parameters based on the model outputs results in a 1.5% increase in annual oil production, which offers significant guidance for the efficient development of similar oil reservoirs. In this study, the connectivity method was applied to multi-layer real reservoirs for the first time, and the injection and production volume of injection-production wells were repeatedly updated based on multiple iterations of water injection efficiency. The correctness of the method was verified by conceptual calculations and then applied to real reservoirs. So that the oil field can increase production in a short time, and has good application value.


2016 ◽  
Vol 63 (5) ◽  
pp. 414-420 ◽  
Author(s):  
Wei Yan ◽  
Yong Xiang ◽  
Wenliang Li ◽  
Jingen Deng

Purpose This paper aims to establish the downhole CO2 partial pressure profile calculating method and then to make an economical oil country tubular goods (OCTG) anti-corrosion design. CO2 partial pressure is the most important parameter to the oil and gas corrosion research for these wells which contain sweet gas of CO2. However, till now, there has not been a recognized method for calculating this important value. Especially in oil well, CO2 partial pressure calculation seems more complicated. Based on Dolton partial pressure law and oil gas separation process, CO2 partial pressure profile calculating method in oil well is proposed. A case study was presented according to the new method, and two kinds of corrosion environment were determined. An experimental research was conducted on N80, 3Cr-L80 and 13Cr-L80 material. Based on the test results, 3Cr-L80 was recommended for downhole tubing. Combined with the field application practice, 3Cr-L80 was proved as a safety and economy anti-corrosion tubing material in this oil field. A proper corrosion parameter (mainly refers to CO2 partial pressure and temperature) can ensure a safety and economy downhole tubing anti-corrosion design. Design/methodology/approach Based on Dolton partial pressure law and oil gas separation process, CO2 partial pressure profile calculating method in oil well is proposed. An experimental research was conducted on N80, 3Cr-L80 and 13Cr-L80 material. A field application practice was used. Findings It is necessary to calculate the CO2 partial pressure properly to ensure a safety and economy downhole tubing (or casing) anti-corrosion design. Originality/value The gas and oil separation theory and corrosion theory are combined together to give a useful method in downhole tubing anti-corrosion design method.


1995 ◽  
Vol 384 ◽  
Author(s):  
M.C. Kautzky ◽  
B.M. Clemens

ABSTRACTIn this paper we report the successful growth of single-phase epitaxial PtMnSb films and multilayers by dc magnetron cosputtering, both in the (001) orientation on MgO(001) and W(001), and in the (111) orientation on Al2O3 (0001). Single-layer films in the thickness range 50Å≤t≤1000Å were grown and characterized using x-ray diffraction (XRD), magneto-optic Kerr effect (MOKE), and vibrating sample magnetometry (VSM). The in-plane orientation relationships, as determined by asymmetric XRD, were PtMnSb[100]∥MgO[110], PtMnSb[100]∥W[100], and PtMnSb[101∥Al2O3[2110]. The crystalline quality of the films was found to depend strongly upon the substrate, growth temperature, film thickness, and presence of a capping layer, but rocking curve widths of 1° or less were achieved on each substrate. Measurement of the in-plane strain showed that the films were almost entirely relaxed, with strains <1%. In-plane magnetization was observed in all cases, with moments and coercivities in the 400-500 emu/cm3 and 100-200 Oe ranges respectively. Polar Kerr spectra showed large rotations (0.75° - 1.03°), whose peak wavelengths appear to depend on both film structure and optical interference effects.


Author(s):  
E. Yu. Kulikova ◽  
Ju. A. Sergeeva

One of the problems of functioning of coal industry enterprises is the formation of mine waters, which are discharged into water bodies and cause their dangerous pollution. The total volume of water pumped by the enterprise includes up to 15 % for the recycling cycle, the remaining 85% is discharged to surface water bodies. As a result, the ecological balance of coal regions is disturbed, their sanitary and hygienic state on the environment worsens, and the quality of coal is reduced due to the intake of polluted water for technological operations. The volume of mine water contamination increases during mining operations at deeper horizons and in difficult mining and hydrogeological conditions. In turn, this leads to pollution and depletion of underground aquifers and the formation of environmental risk factors. In Kuzbass, all these factors contribute to the development of water crisis, since the state of surface reservoirs has already reached a critical limit. Especially dangerous is the process of liquidation of mines. Closing mines and sections disrupt natural water flows, resulting in all water from the aquifers going to deeper horizons. More pollutants enter the water, which poison the underground hydrosphere of the regions. The paper analyzes the pollutants entering the underground and surface hydro grid at coal-fired plants and offers a Conceptual model for minimizing the risk of water pollution.


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