The SPE has split the former "Management & Information" technical discipline into two new technical discplines:
- Data Science & Engineering Analytics
The SPE has split the former "Management & Information" technical discipline into two new technical discplines:
|Theme||Visible||Selectable||Appearance||Zoom Range (now: 0)|
Xiang, Chuangang (Exploration and Development Research Institute of Daqing Oilfield Co. LTD) | Fu, Zhiguo (Exploration and Development Research Institute of Daqing Oilfield Co. LTD) | Zhuang, Xiangqi (Schlumberger) | Gao, Bei (Schlumberger) | Chen, Yingru (Schlumberger)
Abstract In order to improve the production of Gulong shale oil from well stimulation, a Geoengineering integrated model was established through integration of geological modeling, geomechanics modeling, fracturing modeling and reservoir simulation from QH working pad in Daqing oilfield, Northeast China. Based on integrated modeling workflow and study, key stimulation parameters such as stage interval, clusters of stage, frac liquid volume and proppant volume, well spacing were quantitatively optimized. Optimization study indicated 70-80m stage interval, 10m cluster interval (7 clusters per stage), frac volume 1,400 m per stage, proppant volume 140 m per stage are best parameters in QH pad and 400 m well spacing staggering across zones are best well pattern to QH pad. The study results are of great significance to the realization of large-scale rapid production increase and profitable development for Gulong shale oil reservoirs.
Wu, Xingcai (Startwell Energy Co. Ltd) | Zhu, Yan (No. 1 Oil Production Plant of Daqing Oilfield, CNPC) | Liu, Xiaoying (No. 1 Oil Production Plant of Daqing Oilfield, CNPC) | Zhang, Song (Research Inst. of Petroleum Exploration and Development, CNPC) | Gao, Shang (Fangxing oilfeld, Daqing, CNPC) | He, Jingang (No. 1 Oil Production Plant of Daqing Oilfield, CNPC) | Wu, Hao (No. 1 Oil Production Plant of Daqing Oilfield, CNPC) | Wang, Chunyao (No. 1 Oil Production Plant of Daqing Oilfield, CNPC) | Ye, Yinzhu (Research Inst. of Petroleum Exploration and Development, CNPC) | Cui, Guoyou (Startwell Energy Co. Ltd) | Lu, Qiong (Startwell Energy Co. Ltd)
Abstract Large scale polymer flooding in Daqing Oilfield achieved great success. The average recovery degree of these oilfields after polymer flooding has reached 52.5%, and the average water cut has reached 96.0%. It is urgent to find an effective technical method for further EOR. Targeting the highly dispersed remaining oil in the post polymer flooding reservoirs, the continuous phase polymer solution in ASP technology was replaced by nano-micron particle polymer dispersion to realize optimization for EOR mechanism, so the ASP technology was upgraded. The field test, has been completed the slug injection, and achieved obvious EOR effect. The ASP slug design with HPAM solution as the main displacement phase was abandoned. A type of water dispersion of nano-micron particle polymer as the main displacement phase was designed to replace the "P" in traditional ASP slug, so that the flowing control mechanism of "P" was optimized. Through synchronous diversion and displacement, it can initiate and sweep the remaining oil dispersed in relatively small pores. A large three-dimensional physical model with the size of 60 × 45 × 4.5cm was made to simulate the real development history of water injection and polymer flooding of the reservoir, based on which, the performance of the upgraded ASP was modeled. Furthermore, the program was designed and optimized by numerical simulation. The physical simulation fitting experiment of the development history of water flooding and polymer flooding shows that the coincidence rate is 93%+. After polymer flooding, the upgraded ASP further improved the recovery by 15.2 percent. The optimized scheme of numerical simulation is to inject 0.5PV of new ASP slug. Under the precondition of the historical recovery degree of 55.8% and water cut of 98.44%, the new ASP is expected to improve the recovery by 7.9% within 10 years. At present, the field test of ASP slug injection has just been completed, and remarkable results have been achieved, The daily oil production has increased by 60%, and the water oil ratio has decreased from 61.9 to 38.4. The daily oil production of some producers has increased by 2 to 3 times, and the recovery has increased by 5.2%. The field trial proves that the oil displacement mechanism of nano-micron-particle-polymer ASP flooding chemical system is more advanced and the displacement efficiency is higher than that of the traditional ASP flooding, and the oil recovery can be further enhanced for similar reservoirs under extreme conditions after polymer flooding. The traditional ASP technology is expected to have great upgrading and developing.
Summary This paper presents a systematical review of the largest polymer flood project in the world, applied to multilayered, heterogeneous sandstone reservoirs in the giant Daqing Oilfield in China. First, reservoir and fluid characteristics are highlighted to understand the heterogeneity of the reservoir. Next, the project history is summarized, including laboratory studies, pilot tests, commercial tests, and fieldwide applications. Third, typical polymer flood performance and reservoir management measures are presented. Finally, key understandings and lessons learned from more than 50 years of experience are summarized. The La-Sa-Xing Field in the Daqing Field Complex contains three types of reservoir sands: Type I sand with high permeability, Type II sand with medium permeability, and Type III sand with low permeability. Polymer flood was studied in the laboratory in the mid 1960s, followed by small-scale pilots beginning in 1972 and industrial-scale pilots starting in 1993, all of which successfully reduced water cut and enhanced oil recovery. Fieldwide application commenced in 1996, targeting the Type I sand. With Type II sand being brought onstream in 2003, the project achieved a peak production of 253,000 BOPD in 2013. Polymer flood reduced water cut by 24.8%. Reservoir management measures, such as zonal injection, profile modification, hydraulic fracturing in low-permeability sand, and injection optimization, proved to be effective. Based on the water-cut performance, production can be divided into four stages: (1) water-cut decline, (2) low water cut, (3) rebound, and (4) water chase. Fit-for-purpose improved-oil-recovery measures were implemented for each stage to improve production performance. Key understandings and lessons learned include the following: (1) Polymer flood improves both sweeping and displacing efficiencies; (2) high interlayer permeability contrast leads to low incremental recovery; (3) variable well spacing should be adopted for different reservoir types; (4) adoption of large molecular weight (MW) and large slug size greatly enhances recovery; and (5) salt-resistant polymer is beneficial for produced water reinjection in Type II sand; (6) zonal injection increased swept reservoir zones by 9.8% and swept pay thickness by 10.3%; (7) profile modifications helped improve vertical conformance in injection wells and led to enhanced sweeping efficiency and extended low water-cut stage; and (8) optimization-recommended well spacing for Type I, Type II, and Type III sands is 10–15.5, 5.6–7.6, and 2.5–3.6 acres, respectively. In comparison with generally 6–8% incremental recovery by polymer flood in the industry, this project achieved an impressive incremental recovery of 12%, enhancing the oil recovery factor from 40% by primary recovery and waterflood to 52% stock tank oil initially in place (STOIIP). The progressive approach from laboratory experiments through pilots and finally to field application is a best practice for applying polymer flood fieldwide for a giant field such as the La-Sa-Xing Field.
Abstract This paper presents a systematical review on the largest polymer flood project in the world, applied to a giant field with muti-layered, heterogeneous sandstone reservoirs. In this paper, we begin by talking about reservoir and fluid characteristics to provida basic understanding of reservoir heterogeneity. Next, the authors summarize the project history from laboratory studies, through pilot tests, commercial tests to field wide application. Then, we illustrate typical polymer flood performance and reservoir management for improving EOR process performance. Finally, key understandings and lessons learned based on over 50 years’ polymer flood practice are presented. Three types of reservoir sandsare developed in this field: higher permeability sand (Type I), medium permeability sand (Type II) and relatively low permeability sand(Type III). Prior to the start of field wide polymer flood in Type I reservoir in 1996, more than ten pilot and commercial tests had been implemented. With Type II reservoir polymer flood coming on stream in 2003, the project achieved a peak production of 253,000 BOPD in 1993. Polymer flood reduced water-cut by 24.8%. Effective reservoir management activities include zonal polymer solution injection, profile modification, fracturing of low permeability sand, and injection slug size optimization. During fieldwide polymer flood, the water-cut performance is characterized by four stages:(1) initial declining, (2) sustained low value, (3) rebound and (4) high water-cut chase-water injection. Operators implemented fit-for-purpose measures in each stage to improve the EOR process performance. Key understandings and lessons learned include: (1) polymer flood improves both sweeping and displacing efficiencies; (2) high inter-layer permeability contrast leads to lower incremental recovery; (3) variable well spacing should be adopted on each type of the reservoir sands; (4) optimized high polymer MW and large polymer slug greatly improve recovery; and (5) salt-resistant polymer in particular is beneficial for produced water re-injection in Type II reservoir sand. Compared with 6% to 8% incremental recovery by polymer flood in most pilots and partial application cases in the industry worldwide, this successful large-scale project improved recovery by 12% over water flood. The finding of improved displacing efficiency by polymer flood further expands the understanding of its oil-displacing mechanism. Effective fit-for-purpose reservoir management measures during life-cycle polymer flood process provide experiences and lessons learned.
Abstract Chemical flooding technique is the dominating EOR technique in China. Polymer flooding has entered into industrialized applications and has been applied on a large scale in Daqing sandstone reservoir. Now polymer flooding is expanding to other reservoirs such as conglomerate reservoir, complex fault block reservoir and high temperature and high salinity reservoir. The good EOR effect achieved by polymer flooding is closely related to the key innovation technologies. Recent progress of field tests and application of polymer flooding enhanced recovery (EOR) in China was summarized in this paper. Key technical innovations and field application effects was introduced. The challenges faced and the development direction of polymer flooding technology was discussed. Polymer flooding has been applied in Daqing Oilfield from medium-high permeability reservoirs (type I reservoirs) to medium-low permeability reservoirs (type II reservoirs) with poor petrophysical properties. In addition, polymer flooding solution was prepared by dilution of produced water instead of fresh water. 13% incremental oil recovery in average has been obtained. Polymer flooding has expand apply to conglomerate reservoir in Xinjiang Oilfield, complex fault block reservoir in Dagang Oilfield and high temperature and high salinity reservoirs in Shengli Oilfield, the application results was also successful by solving bottleneck technical problems. A series of technologies have been developed for industrialization application of polymer flooding during tests and application. The key innovations are: polymer product evaluation and molecular weight optimization techniques; development of numerical simulation software and optimization of field test scheme; high efficient injection equipment and process; profile modification during polymer flooding; separated layer injection technique; separated molecular weight and pressure injection technology; anti-eccentric wear lifting technology; fracturing and injection technology; dynamic tracking and adjustment technology; produced liquid treatment technology. These innovative techniques ensure good results of polymer flooding in field applications. The key points and practical application of these technologies are illustrated with examples. Polymer flooding is the leading EOR technology for medium and high permeability reservoirs. Polymer flooding has been applied on a large scale and is being extended to more complex reservoirs. Facing new technical challenges, it is necessary to continuously strengthen the research and development of new functional polymers, research of reservoir adaptability and continuously technological innovation of supporting technology for different types of reservoir application.
Abstract Chemical EOR (CEOR) technique is the dominant EOR technique in China. Recent progress of and remaining challenges in CEOR technologies in China is summarized in this paper. Key technical progress and field application results are also introduced. As one of the mature chemical flooding technologies, polymer flooding has entered into industrialized applications stage in sandstone reservoirs. Polymer flooding has been applied in Daqing oilfield and 13% incremental oil recovery on average has been obtained over the past few decades. Polymer flooding has been also successfully applied to conglomerate reservoir in Xinjiang oilfield and complex fault block reservoir in Dagang oilfield. The most important CEOR technique is the alkali-surfactant-polymer (ASP) and surfactant-polymer (SP) flooding. The field tests showed that ASP flooding can significantly increase the oil recovery by 19-26% of OOIP. High efficiency and low cost surfactants for ASP formula were developed and ultralow interfacial tension was achieved. To avoid the negative effects of the alkali, five SP flooding field tests have been conducted in different reservoir types. The third CEOR technique is foam flooding. Many pilot tests have been performed, most projects obtained favorable recovery factor. The remaining challenges are how to develop more stable foam formula and inject the foam more effectively. Polymer flooding is now expanding to complex reservoirs. ASP/SP flooding will be the leading EOR technology for high permeability reservoirs in China. The target reservoir is extended from sandstone reservoirs to complex fault block reservoirs and conglomerate reservoirs. Foam flooding is one of the potential CEOR technologies, especially in high temperature and high salinity reservoirs.
The Ocean Bottom Flying Node (OBFN) has been widely used for offshore oil exploration, water cruising, and monitoring. However, due to the limitation of its own energy supplies, the maneuvering of the OBFN is restrained over very short distances. To improve its cruising efficiency in order to better complete operational tasks, optimal hydrodynamic performance of the OBFN is vitally important. The hydrodynamic performance optimization of the OBFN is conducted via computational fluid dynamics in this paper. The drag reduction performance and capsule volume are considered as optimization parameters, through which the configuration of the OBFN is optimized based on the optimization theory. The results show that the resistance of the OBFN decreased significantly as volume increased. Introduction To meet the needs of large-scale network deployment in seismic exploration applications, Harbin Engineering University (HEU) conceived a new special autonomous underwater vehicle (AUV), the Ocean Bottom Flying Node (OBFN), which combines ocean bottom node (OBN) and AUV techniques. Equipped with multifunctional sensors, it can meet multitask requirements such as long-term sitting, sea cruising, marine resource exploring, and submarine seismic monitoring. A schematic of OBFN is shown in Fig. 1. The OBFN relies on its own energy supply when sailing underwater and can cruise only for a short distance because of its limited energy supply. It is necessary to improve its cruising efficiency and reduce its energy consumption. However, its large number of internal parts and complicated external molding make the optimization design of OBFN very challenging. At present, the traditional optimization methods are based on empirical experiences, which are inefficient and also cannot obtain a global optimal solution. In recent years, breakthroughs in computational fluid dynamics (CFD) and modern optimization theory have accelerated the development of hydrodynamic optimization. AUV hydrodynamic optimization presents the characteristics of multidisciplinary cross-cutting and multi-objective optimization.
Han, Haochen (CNPC Engineering and Technology R&D Company) | Zhang, Yong (CNPC Engineering and Technology R&D Company) | Chen, Jia (CNPC Materials Procurement Center) | Sun, Qi (CNPC Engineering and Technology R&D Company) | Fang, Zhimeng (CNPC Engineering and Technology R&D Company) | Li, Hexiang (CNPC Engineering and Technology R&D Company) | Liu, Zeng (CNPC Engineering and Technology R&D Company) | Zhang, Guobin (CNPC Engineering and Technology R&D Company)
Abstract High-speed wired drill pipe and its corresponding communication technology not only can achieve high-speed transmission rate and high-capacity, but also can realize real-time monitoring and dual-way communication in whole section, which can prevent downhole problems effectively. As a series system, the homogeneity and robustness of these wired drill pipes are crucial. This paper focuses on how to overcome the difficulty in manufacturing process of information drill pipe and complete the validation test. In order to guarantee the quality of information drill pipe and satisfy the technological requirements of mass production, we optimize the manufacturing process and put forward reasonable test techniques. The optimizations of manufacturing process include the analysis on constant tension of pressure pipe, quantitative cutting pipe and perforation in pipe nozzle. The testing techniques includes magnetic coupling coil impedance test, high pressure test, communication performance test of both single pipe and series system. The test result can be judged and evaluated by the attenuation value of the signal attenuation test and the signal reflection waveform as well as sealing reliability. With the help of the optimization of the manufacturing process and the application of new tooling, the quality and robustness of information drill pipe is improved obviously. Pass rate in primary assembly is increased from 70% to 92%. After the second assembly, pass rate can be increased to 99.5%. Besides, the work efficiency is greatly improved and the process requirements of mass production are satisfied. The validation test can screen out the drill pipe with poor quality and performance effectively thus to improve the reliability of the whole system. By means of the improvement of manufacturing and the validation test, the comprehensive pass rate of information drill pipes is increased from 84% to 95%. During three field tests in Jilin and Daqing Oilfield, the information drill pipes functioned well and accomplished all the test tasks successfully. High-speed wired drill pipe can improve the downhole data transmission on a large margin. The theorical transmission rate can be up to 100 kbps, 10,000 times as much as the traditional mud impulse telemetry. The manufacturing optimization and test technology can guarantee the performance and realize downhole data highway.
Abstract In previous work, we demonstrated that EOR chemicals had minor effect on topside processes in terms of separation, corrosion and scale inhibition. Regarding the oil/water separation, the most noticeable effect was a deterioration in separated water quality that was deemed manageable. This paper will further investigate the impact of produced polymer and surfactant on the quality of separated water. To mimic the separation plant potential feed and operations, experimental work has been carried out by preparing oil/brine mixtures at different surfactant/polymer concentrations with oilfield additives. Three main parameters have been varied: surfactant/polymer (SP) concentration, temperature, and water cut. The final test matrix consists of 24 tests. We first assessed the impact of EOR additives on the type of generated emulsions (O/W or W/O). Then we performed bottle tests taking into account the different operating parameters in order to investigate the kinetics of water/oil separation. Finally, we carried out physical-chemical analyses on the separated water in order to evaluate its quality. In terms of concentration effects, the results suggest that SP concentration had minimal impact on pH and density of the aqueous phase. Bottle tests showed that phase inversion was obtained at intermediate and high SP concentrations for both water cuts. In addition, separated water quality deteriorated in systems of intermediate SP concentration and slightly improved at high concentration at 32 °C. At 54°C, higher SP concentrations resulted in poorer water quality. Kinetics of separation accelerated with higher SP concentrations. In terms of temperature effects, a slight decrease in both viscosity and density of emulsions was observed at higher temperatures. Kinetics of separation also improved with higher temperatures, as did the quality of the separated water. In terms of water cut effects, viscosity and density of the aqueous phase were not impacted. Moreover, phase inversion of the emulsion (from water-in-oil to oil-in-water) occurred when water cut increased from 75 to 85% without SP. With SP, oil-in-water emulsions were observed for both water cuts. Kinetics of oil/water separation increased with the higher water cut; however, no clear tendency on water quality was observed. with water cut. In conclusion, we reconfirm that SP production, at least for the investigated formulations, will have a negligible effect on separation. The result will lead to deterioration in separated water quality; however, the level of deterioration is manageable and would not affect conventional practices of disposal in oilfields for pressure maintaining purposes. At last, this study layout laboratory protocols to perform such process-assurance.
Cheng, Cheng Jie (Daqing Oilfield Company Ltd., Daqing) | Liu, Bo Hai (Exploration and Development Research Institute of Daqing Oilfield Company Ltd., Daqing) | Gao, Qian (Exploration and Development Research Institute of Daqing Oilfield Company Ltd., Daqing) | Yan, Wei (Exploration and Development Research Institute of Daqing Oilfield Company Ltd., Daqing) | Chen, Lin Wen (Exploration and Development Research Institute of Daqing Oilfield Company Ltd., Daqing) | Liu, Chao Guo (Exploration and Development Research Institute of Daqing Oilfield Company Ltd., Daqing) | Zhou, Quan (Production Engineering Research Institute of Daqing Oilfield Company Ltd., Daqing) | Han, Hui Pei (Exploration and Development Research Institute of Daqing Oilfield Company Ltd., Daqing)
Abstract The blocks of polymer flooding have gradually entered into the stage of chase water flooding after polymer flooding in Daqing Oilfield and the comprehensive water cut is close to the exploitation limit of 98%. So it is urgent to develop some new technologies to further enhance oil recovery after polymer flooding. On the basis of laboratory research, a field test of alkali/surfactant/polymer flooding was carried out after polymer flooding in Daqing Oilfield in 2015, which achieved good development effect, but the polymer concentration was relatively large. Based on the field test of alkali/surfactant/polymer flooding, a new technology of the lower initial viscosity gel/alkali/surfactant/polymer flooding has further been studied according to the technical route combining plugging, adjusting and displacing, which can reduce the polymer dosage greatly under the premise of ensuring good oil displacing effect. In this paper, some laboratory studies are carried out, which realize significant technology breakthrough. Firstly, the adjusting and plugging agent of lower initial viscosity gel is screened out, which can be injected into the high permeability layers of low flow resistance like the water and migrate to the deep location of the high permeability layers and then gelatinize on spot. Therefore it can plug high permeability layers effectively and does not pollute the middle and low permeability layers at the same time. Secondly, the injection parameters of lower initial viscosity gel/alkali/surfactant/polymer system are optimized. The results of laboratory experiments show that the lower initial viscosity gel/alkali/surfactant/polymer system can enhance oil recovery by 13.5% OOIP under the optimal injection parameters, which is 1.2% OOIP more than that of the alkali/surfactant/polymer flooding and can save polymer dosage by 17.8%. In view of the good results obtained in laboratory experiments, the scenario design of field test is carried out and the incremental oil recovery is 10.1% OOIP predicted by numerical simulation. The field test is expected to start chemical flooding in 2021.