Dagang Oilfield Group Co.

Tianjin, China

Dagang Oilfield Group Co.

Tianjin, China
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Pavlova-Kostryukova N.K.,Russian Academy of Sciences | Tourova T.P.,Russian Academy of Sciences | Poltaraus A.B.,RAS Engelhardt Institute of Molecular Biology | Feng Q.,Dagang Oilfield Group Co. | Nazina T.N.,Russian Academy of Sciences
Microbiology (Russian Federation) | Year: 2014

Microbial diversity and biogeochemical processes of the Gangxi bed with low-mineral water and a temperature gradient from 35 to 54°C were studied. The 16S rRNA gene clone libraries (over 800 clones) were obtained from microbial DNA isolated from formation water and from the primary enrichment cultures for fermenting, sulfate-reducing, methanogenic, and aerobic organotrophic prokaryotes. While both sulfate reduction and methanogenesis were registered in formation water by radioisotope techniques, the genes of sulfate-reducing prokaryotes were not revealed in the 16S rRNA gene clone library from formation water. The 16S rRNA genes of Methanobacterium congolense and Methanococcus vannielii predominated among archaeal sequences retrieved from formation water, while the genes of Methanothermobacter thermoautotrophicus, Methanomethylovorans thermophila, and Methanoculleus sp. predominated in the combined library from enrichment cultures. In the library of Bacteria 16S rRNA genes from formation water, the genes of thermophilic fermentative bacteria of the family Thermoanaerobacteriaceae predominated; the remaining sequences belonged to mesophiles (genera Brevundimonas, Sphingomonas, Oxalicibacterium, and Stenotrophomonas), the phylum Chloroflexi, and unidentified bacteria. The combined library from enrichment cultures, contained, apart from the sequences of the family Thermoanaerobacteriaceae, the genes of fermentative bacteria (genera Anaerobaculum, Coprothermobacter, Thermanaerovibrio, Soehngenia, Bacteroides, and Aminobacterium and the order Thermotogales), of aerobic hydrocarbon-oxidizing bacteria (genera Pannonibacter and Pseudomonas), and of sulfate reducers (genera Desulfomicrobium, Thermodesulfovibrio, and Desulfotomaculum). High coverage was shown for bacterial (97.6%) and archaeal (100%) clone libraries, indicating that a significant portion of the microbial diversity in the studied communities was revealed. © 2014, Pleiades Publishing, Ltd.

Xiao Y.,Jilin University | Xiao Y.,Dagang Oilfield Group Co. | Li W.,Jilin University | Xue L.,Jilin University
2nd International Conference on Information Science and Engineering, ICISE2010 - Proceedings | Year: 2010

Sedimentary Micro-Facies pattern recognition system is very important to improve the efficiency of sedimentary Micro-Facies identification. Bayesian Micro-Facies recognition system is consisted of feature extraction, feature memory, Micro-Facies knowledge and Micro-Facies type recognition. Feature Extractor and Micro-Facies recognition are two major components of the system, feature extraction is mainly used to extract the statistical characteristics, geometric characteristics of features and image feature parameters, Micro-Facies identification mainly use Bayesian model recognition method to make Microfacies identification. The system is used in Daqing area, the accuracy rate of Microfacies identification is 85%. © 2010 IEEE.

Meng F.-Y.,China University of Petroleum - Beijing | Li Y.,Chengdu University of Technology | He C.,Dagang Oilfield Group Co. | Xiao D.-Q.,Dagang Oilfield Group Co. | And 3 more authors.
Zhongguo Shiyou Daxue Xuebao (Ziran Kexue Ban)/Journal of China University of Petroleum (Edition of Natural Science) | Year: 2011

According to the principle of sequence stratigraphy and the relationship between the tectonic structure and deposition, the structure pattern and sequence mode were studied on the area of gentle slope of Qikou depression. And the relationship between tectonic structure and deposition was analyzed. Three types of structure unit were discriminated according to the tectonic characteristics on the area of gentle slope of Qikou depression. They were outside-belt, middle-belt and inside-belt respectively. And then three structure patterns were ascertained, they were low angle-multifaults-ramp slope, low angle-multifaults-simplex break slope and high angle-multifaults-complex break slope. Six second order sequences and sixteen third order sequences were identified, and the sequence frame was built and the deposited characteristics in interior sequence were described in Shahejie formation in the area. The distribution of the sequence controlled by tectonic effect was analyzed in each of structure pattern. The results show that sequences are of incompleteness. Low-order system tract deposited in a few local regions. Lacustrine trans gressive system tract and high-order system tract deposited in all the depression. The number of sequences decreases, the thickness of sequences reduces and the completeness of sequences decreases from the north to south. The type of sequence stratigraphy and formation structure are controlled by the pattern of tectonic structure.

Zhang F.,China University of Petroleum - East China | Guo J.-F.,Dagang Oilfield Group Co. | Wang X.-G.,China University of Petroleum - East China
Jilin Daxue Xuebao (Diqiu Kexue Ban)/Journal of Jilin University (Earth Science Edition) | Year: 2010

Air drilling technology, an underbalanced drilling method, affects the neutron porosity logging. The neutron porosity calculation model in open hole has been established, and the neutron transport processes were simulated with Monte Carlo method under the condition of different porosity, lithology, shale content, hole size and air pressure.After studying the ratio of thermal neutron count and porosity, it could be concluded that the thermal neutron count increase at first, then after a point, decrease with the increase of porosity. The count ratio from limestone is higher than that of sandstone; and the higher the shale content, the larger the ratio. Moreover, the ratio is influenced by hole size; it is especially significant for large porosity formation; the bigger the hole size is, the smaller the ratio is; thus makes the determination of neutron porosity more difficult. However, the gas pressure has little effect over the ratio of thermal neutron. As a result, in air drilling, neutron porosity should be re-calibrated and correction should be done according to lithology, shale content and borehole size.

Liu T.,Dagang Oilfield Group Co. | Jin S.,Dagang Oilfield Group Co. | Wang L.,Dagang Oilfield Group Co.
Drilling Fluid and Completion Fluid | Year: 2014

An anti-corrosion cement slurry was formulated by adding an inert anti-corrosion additive and an anti-channeling additive into a high temperature cement slurry. This anti-corrosion cement slurry satisfied the needs for cementing in wells penetrating H2S and CO2 rich formations. Evaluation was conducted on the base fluid and the required additives for the cement slurry. The anticorrosion performance and engineering applicability of the cement slurry were analyzed through laboratory experiments in terms of the integrated performance, anti-channeling ability and effect on the bond strength of the cement sheath interfaces of the cement slurry. The experiment results showed that the anti-corrosion performance of the set cement was remarkably enhanced if cement slurry was treated with the anti-corrosion additive. The formulated anti-corrosion cement slurry was used successfully in Well Qian4-18 penetrating Qianmiqiao buried hill, satisfying the needs for drilling operation.

Li S.,Dagang Oilfield Group Co. | Zhang J.,Dagang Oilfield Group Co. | Yin L.,Dagang Oilfield Group Co. | Ju B.,Dagang Oilfield Group Co.
Drilling Fluid and Completion Fluid | Year: 2015

The Nanpu #3 Structure in Jidong Oilfield has big reserves which are deeply buried. Deep and ultra-deep wells have been drilled in this area with high bottom hole temperatures and large horizontal displacements. A high temperature KCl drilling fluid, BH-KSM, was formulated for use in this area. BH-KSM remains stable at temperature up to 200℃, and has excellent inhibitive and sealing capacity, and tolerance to CO2 contamination, essential for dealing with borehole instability, creep of formation at elevated temperatures, and contamination to drilling fluid by formation fluid in Nanpu #3 Structure. Technology for field application of the BH-KSM was engineered for maximum functioning of the mud. Field application of BH-KSM in 10 wells in the Nanpu #3 Structure showed that percent hole enlargement in the Dongying Formation, known for its being water sensitive and prone to collapse, was less than 7%, and the minimum of which being only 3.98%. The mud had stable rheology during drilling. HTHP filter loss can be kept under 12 mL. Cuttings over shale shakers were hard and had good integrity, illustrating good inhibition of the BH-KSM. Good carrying capacity of the mud resulted in satisfactory hole cleaning and increasing rate of penetration. ©, 2015, North China Petroleum Administration Drilling Technology Research Institute. All right reserved.

Li Y.,Northeast Petroleum University | Ai C.,Northeast Petroleum University | Liu Y.,Dagang Oilfield Group Co. | Gao C.,Northeast Petroleum University
Open Fuels and Energy Science Journal | Year: 2014

The open hole completion CBM borehole wall intersects with the weak surface such as cleats and fractures. In the process of hydraulic fracturing, the fractures may origin from coal body or cleats, which makes the rupture mechanism and rupture models of the borehole wall being different from the conventional reservoirs. The previous model for calculating breakdown pressure of open hole completion borehole wall considering tension failure has poor applicability for calculating breakdown pressure. Considering the spatial relationship of the intersection of borehole wall and cleats, analyzing the stress state of borehole wall rock and cleats wall, and basing on elastic mechanics and fracture mechanics, the breakdown pressure calculation model for CBM open hole completion hydraulic fracturing was established. In the model, fractures initiate from coal rock body, tensile failure along with face cleats, shear failure along with face cleats, tensile failure along with butt cleats and shear failure along with butt cleats five kinds of damage modes were considered. According to example calculation, the breakdown pressure of HX-L1 well calculated using the model is 14.81 MPa. The actual pressure obtained by bottom hole pressure gage is 15.42 MPa, and the relative error is 3.96%. The calculated result agrees with the actual conditions. It can be concluded that the model can be used to calculate the breakdown pressure for open hole completion CBM well hydraulic fracture. © Yuwei et al.

Tang J.B.,Northeast Petroleum University | Wu W.X.,Northeast Petroleum University | Zhang Z.X.,Dagang Oilfield Group Co.
Advanced Materials Research | Year: 2014

Using the physical simulation experiment, for the new active polymers, common carve and polymer 25 million to act on interfacial tension test, the results indicate, interfacial tension for common carve and polymer 25 million is about 10 mn/m. and interfacial tension for the active polymer is about 1 mn/m. Rheology showed that the viscosity and elasticity of active polymer solution were higher than 25 million polymer.In liquidity experiment, active polymer solution has the better liquidity than in 25 million polymers in the low permeable formation,the flooding effect of active polymer is better than 25 million polymer and common carve polymer.the better injection and better oil displacement features of active polymer are suitable for low permeability reservoirs to improve oil displacement effect. © (2014) Trans Tech Publications, Switzerland.

Wu W.X.,Northeast Petroleum University | Tang J.B.,Northeast Petroleum University | Zhang Z.X.,Dagang Oilfield Group Co.
Applied Mechanics and Materials | Year: 2013

With the Interfacial tension test, researched the active agent interface behavior of HXJ-1 and HXJ-2.Test study indicates that the alkali concentration less than 0.6% and 1.2% respectively, the active agent HXJ-and HXJ-2 can form ultralow interfacial tension, besides the area of ultralow interfacial tension formed by HXJ-1 is larger than HXJ-2. As can be seen from the chorogram chart of foam composite index, without alkali and polymer, the two kinds of surface active agent generate the foam composite index similarly in the different density of active agent. The exist of alkali is not effect positively for the formation of super foam in the system, and adding appropriate(<200mg/L) polymer can increase the system foam effectively. When add the alkali or polymer, the area of super foam formed by HXJ-1 will larger than HXJ-2.By the percentage of foam quality, the HXJ-1 required less amount of active agent and concentration to transfer the whole system into the foam than HXJ-2, may draw a conclusion that the HXJ-1 is more easily foam than HXJ-2. The chemical flooding recovery efficiency of HXJ-1 improved three percentage point compared with HXJ-2. © (2013) Trans Tech Publications, Switzerland.

Liu W.,Dagang Oilfield Group Co.
Drilling Fluid and Completion Fluid | Year: 2015

Molecular design of filter loss reducer was done with control over some factors affecting synthesis reaction such as the mass ratio of polymerization monomers, amount of initiators and reaction temperatures. The effort produced a filter loss reducer for oil well cement, BZF-L1, a copolymer made from five monomers. This filter loss reducer, according to laboratory test, works at temperatures up to 180 °C, and at salinity of cement slurry up to saturation. At 180 °C, by adjusting the concentration of BZF-L1, cement slurries mixed with water of any salinity from fresh water to saturation had their filter losses kept under 50 mL. Cement slurries treated with BZF-L1 had thickening time, compressive strength, settling stability, rheology and free water content that all satisfied the needs for field operation. One of BZF-L1's success cases was its use in cementing the Well 139X1.

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