Zhang Y.,Dagang Oilfield Company |
Lu R.,University of Tulsa |
Forouzanfar F.,University of Tulsa |
Reynolds A.C.,University of Tulsa
Computers and Chemical Engineering | Year: 2017
Compared to the CO2 flooding, the alternative injection of water/surfactant solution and CO2 gas (WAG/SAG) can provide good control over the mobility ratio, stabilize the displacement front and improve the macroscopic sweep efficiency of the flooding. We show that the performance of a WAG/SAG flood can be significantly improved by optimizing the locations and optimizing rates or pressure in order to avoid gas/water channelling and improve sweep efficiency. To maximize the life-cycle net present value (NPV) for a WAG/SAG process, we implemented a steepest ascent algorithm combined with a simplex stochastic gradient to find the optimal well trajectories and controls. Both simultaneous and sequential approaches for the joint optimization of well locations and controls are investigated for a synthetic channelized reservoir model. Well spacing constraints are also included in the optimization process using the penalty method in order to keep the distance between wells greater than a specified minimum value. Four synthetic reservoir problems are studied and optimized to illustrate the viability of the methodology. © 2017 Elsevier Ltd
Zhang Z.-P.,Dagang Oilfield Company
Natural Gas Geoscience | Year: 2014
The Cenozoic Qikou Sag is a typical extensional faulted basin. The faults' character and it's evolution played a key role in hydrocarbon accumulation. In this article we summarized the main characteristics of the faults, and demonstrated the role played by the faults on hydrocarbon conduction and seal process. We divided the Cenozoic faults into three fracture systems, and found that the faults characteristics, the structure style, the tectonic stress state coupling with hydrocarbon reservoir formation stages controlled the conducting or sealing state of the faults to the reservoir and finally formed three typical hydrocarbon reservoir formation modes.
Xu P.,Petrochina |
Xu P.,China University of Petroleum - East China |
Cheng Y.,China University of Petroleum - East China |
Liu X.,Petrochina |
And 3 more authors.
Shiyou Kantan Yu Kaifa/Petroleum Exploration and Development | Year: 2013
Based on the explosive fracturing simulation experiment for low permeability reservoir, growths of the cracks produced by the explosive fracturing in the samples were analyzed. And associated with fractal geometry theory, the cracks fractal characteristics were studied and the influences of explosive quantity and confining pressure on the cracks fractal dimension were analyzed. Different explosive quantities and confining pressures under which the simulation experiment was carried out were designed. After the experiment, the fractal dimension of the cracks produced by explosive fracturing in different samples was got by the box dimension calculation method. The results show that: With the increase of explosive quantity, the amount, length and width of the cracks on the surface of the sample produced by explosive fracturing simulation experiment under the same confining pressure increase. The amount and length of the cracks produced by explosive fracturing under the same explosive quantity decrease with the increase of confining pressure. Under the same confining pressure, the cracks fractal dimension increases with the increase of explosive quantity, and the relationship between them is approximately linear when the confining pressure is relatively low and approximately nonlinear when the confining pressure is relatively high. Under the same explosive quantity, the cracks fractal dimension decreases with the increase of confining pressure. It is suggested that site operation should match the explosive quantity with the confining pressure, and the charge pattern of axial coupling and radial uncoupling should be applied.
Wei Z.,China University of Petroleum - East China |
Chengyan L.,China University of Petroleum - East China |
Minghui Z.,China University of Petroleum - East China |
Helin W.,Dagang Oilfield Company
Petroleum Exploration and Development | Year: 2010
Through building 3D geological models in different drilling time according to the logging while drilling (LWD) data and by updating the previous geological models, the dynamic updating of geological model could enable the acquisition of the spatial distribution of reservoir effectively and find the structural and occurrence changes instantly, so as to modify the former designed borehole track and adjust the drilling track by geosteering, and drill the oil layers in the best way. It can improve the effectiveness of horizontal interval and the drilling benefit. Combined with well logging, geological data and seismic data as well as the LWD data, this method was applied to the drilling of the Guanjiapu Oilfield, and the geological conditions were constrained by the multistage modeling method, to update and improve the Gamma Ray (GR), porosity and permeability models and the accuracy of reservoir random models, especially the sandstone distribution model to ensure the accuracy and reliability of the model. The drilling of Well Zh8-H has shown that the geosteering drilling capability was obviously improved in light of providing accurate geological model timely. © 2010 Research Institute of Petroleum Exploration & Development, PetroChina.
Liu G.H.,Dagang Oilfield Company
Oilfield Review | Year: 2013
Increased production rates in North Dakota led geoscientists to consider using the same techniques to produce oil from source rock in other existing plays, including the Eagle Ford Shale, in Texas, USA, which was the source rock for the massive hydrocarbon accumulation that had produced from the Austin Chalk for 80 years. Service companies refined certain critical technologies in an effort to help operators optimally exploit unconventional plays. These technologies helped operators to drill long horizontal wells and place them accurately within formation sweet spots. Production and completion engineers also sought to improve methods for stimulating the numerous potentially productive intervals pierced by these wells. Refinements to directional drilling assemblies such as the PowerDrive Archer rotary steerable system led to more efficient drilling through higher build rates and improved rates of penetration.
Deng X.,CAS Xishuangbanna Tropical Botanical Garden |
Fang Z.,CAS Xishuangbanna Tropical Botanical Garden |
Liu Y.-H.,CAS Xishuangbanna Tropical Botanical Garden |
Yu C.-L.,Dagang Oilfield Company
Energy | Year: 2011
In this work, hydrotalcite-derived particles with Mg/Al molar ratio of 3/1 were synthesized by a coprecipitation method using urea as precipitating agent, subsequently with (MHT) microwave-hydrothermal treatment, and followed by calcination at 773 K for 6 h. These particles were micro-sized mixed Mg/Al oxides as characterized by SEM and AFM. But actually they were nanosized according to the calculations from XRD data. Because of their strong basicity, the nanoparticles were further used as catalyst for biodiesel production from Jatropha oil after pretreatment. Experiments were conducted with the solid basic catalyst in an ultrasonic reactor under different conditions. At the optimized condition, biodiesel yield of 95.2% was achieved, and the biodiesel properties were close to those of the German standard. The catalyst can be reused for 8 times. © 2010 Elsevier Ltd.
Ma H.,Dagang Oilfield Company
Well Testing | Year: 2014
The development wells at the first region of Chenghai in Dagang oilfield are deviated wells basically, horizontal displacement of which is long, and the water ratio of vertical is high. Well completions in some of high angle wells are used of casing cementing, sand control screen pipe suspension, and independent screen sand control completion in easy sanding formation. Because sand control precision is single, screen is easily plug, and sand control effect is poor, the extrusion gravel packing sand control technology is the use of sand carrying fluid to squeeze the gravel packing method of near well-bore filled with a certain amount of gravel packing, the sieve and well-bore annulus with cyclic filling mode, multilevel sand barrier is formed, and sand prevention effect is good. At the same time, according to the geological the situation of Chenghai deviated wells area features and production of reservoir, and being optimized the construction parameters, the first successful implementation of Zhuanghai8Es-L8 well has been implemented successfully, which has a good effect, improves the high inclination well completion method, and makes true of high efficiency mining to development well.
Liu T.-X.,China University of Petroleum - East China |
Tao Z.-Q.,Dagang Oilfield Company
Zhongguo Shiyou Daxue Xuebao (Ziran Kexue Ban)/Journal of China University of Petroleum (Edition of Natural Science) | Year: 2011
Based on the data from well drilling, geology, well logging and production performance, the reservoir architecture modeling of meandering river was researched using the method of multi-order bounding surface restriction and deterministic modeling in a block of Dagang Oilfield. Reservoir architecture model was established by the method of multi-order bounding surface restriction and limited the architecture element among bounding surfaces on the basis of the sedimentary microfacies model and point-bar architecture, then the reservoir parameter model was established using stochastic modeling under the restrictions of reservoir architecture on the basis of well data analysis. The results show that the space, dip angle and trend of lateral accretion interbeds on the scale, and they must be rectified using the well data during the modeling. The spatial distribution of lateral accretion bodies and lateral accretion interbeds are embodied well by the modeling method of multi-order bounding surface restriction. The attribute modeling under reservoir architecture restriction combines deterministic modeling with stochastic modeling, and the result can reflect the actual situation in the reservoir.
Wu K.,China University of Petroleum - Beijing |
Li X.,China University of Petroleum - Beijing |
Gou X.,Dagang Oilfield Company
Advanced Materials Research | Year: 2013
According to material balance principle, gas/water bearing height in gas reservoir with bottom water could be deduced. Additionally, sweep efficiency could be approximately determined, then based on the equivalent flowing resistance method and critical vertical velocity of bottom water drive, computational model of Critical Producing Pressure Drop during the development of gas reservoir with bottom water could be derived. Therefore, the variance principle of Critical Producing Pressure Drop of horizontal well can be expressed quantitatively, and this paper also analyzes that it is influenced by the ratio of vertical permeability to horizontal permeability, the difference between water and gas density, the ratio of water viscosity to gas viscosity and height for bottom water coning. The results could provide guidelines for the determination of reasonable producing pressure drop and producing rate of horizontal well in gas reservoir with bottom water. © (2013) Trans Tech Publications, Switzerland.
Zhang X.,China University of Petroleum - East China |
Lin C.,China University of Petroleum - East China |
Zhang T.,China University of Petroleum - East China |
Liu W.,Dagang Oilfield Company
Shiyou Kantan Yu Kaifa/Petroleum Exploration and Development | Year: 2011
In shallow sea areas with irregular well pattern and sparse well control, the accuracy of reservoir characterization based on well logging data is too low to satisfy the need of reservoir development research. A seismic sedimentologic study is made in the Block I of Chenghai Oilfield, Dagang. The architecture of braided bars is characterized finely by the inter-calibration and inter-restriction of vertical and horizontal information. Seismic data is processed with technologies of phasing and stratal slicing and then the amplitude on slice is interpreted to obtain the planar distribution of bars. The evolution of braided bars is analyzed with research on slices of different depth. In this research, sand layer of the braided bar in NgI1-1 formation is subdivided into three parts, each of which is formed by a stage of flood deposition. The sedimentary characteristics and evolution revealed by stratal slice interpretation is verified by fine research of vertical and horizontal wells. A sedimentary model is built and will play an important role in horizontal well development and in the architecture characterization of reservoirs without wells.