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:
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Guan, Xu (Exploration and Development Research Institute of PetroChina Southwest Oil & Gasfield Company, Chengdu, China) | Zhu, Deyu (Exploration and Development Research Institute of PetroChina Southwest Oil & Gasfield Company, Chengdu, China) | Tang, Qingsong (PetroChina Southwest Oil & Gasfield Company, Chengdu, China) | Wang, Xiaojuan (Exploration and Development Research Institute of PetroChina Southwest Oil & Gasfield Company, Chengdu, China) | Wang, Haixia (Exploration and Development Research Institute of PetroChina Southwest Oil & Gasfield Company, Chengdu, China) | Zhang, Shaomin (Exploration and Development Research Institute of PetroChina Southwest Oil & Gasfield Company, Chengdu, China) | Deng, Qingyuan (Exploration and Development Research Institute of PetroChina Southwest Oil & Gasfield Company, Chengdu, China) | Yu, Peng (Exploration and Development Research Institute of PetroChina Southwest Oil & Gasfield Company, Chengdu, China) | Yu, Kai (Exploration and Development Research Institute of PetroChina Southwest Oil & Gasfield Company, Chengdu, China) | Huang, Xingning (Downhole service company of Xibu Drilling Engineering Company Limited, Karamay, China) | Xu, Hanbing (CNPC, International HK LTD Abu Dhabi, Abu Dhabi, UAE)
Abstract In recent years, tight sandstone gas as one of the important types of unconventional resources, has been rapid explored and developed. There are large-scale tight sandstone gas production in Sichuan Basin, Ordos Basin, Bohai Bay Basin, Songliao Basin and other basins, and it has become a key part in the area of increasing gas reserves and production in China. Due to the influence of the reservoir characteristics, tight gas reservoirs have low porosity and permeability, and the tight gas can only be effectively developed by improving the conductivity around the wellbore. Therefore, it is required to perform hydraulic fracturing after the completion of horizontal well drilling to improve the permeability of reservoir. It can be seen that hydraulic fracturing is the core technology for efficient development of tight gas resources. The implementation of hydraulic fracturing scheme directly determines the horizontal well production and EUR. This paper describes the workflow of 3D geomechanical modeling, technical application for Well YQ 3-3-H4 reservoir stimulation treatment, and carries out hydraulic fracture propagation simulation research based on 3D geomechanical model. This paper also compares the micro-seismic data with the simulation results, and the comparison results show that the propagation model is consistent with the micro-seismic monitoring data, which verifies the accuracy of the model. This paper clarifies the distribution law of hydraulic fractures in the three-dimensional space of horizontal wells in YQ 3 block, and the research results can be used to provide guidance and suggestions for the optimization of fracturing design of horizontal wells in tight gas of Sichuan Basin.
Zhu, Jun (Vertechs Energy Group) | Zhang, Wei (Vertechs Energy Group) | Zeng, Qijun (Vertechs Energy Group) | Liu, Zhenxing (Vertechs Energy Group) | Liu, Jiayi (PetroChina Southwest Oil & Gas Field Company) | Liu, Junchen (PetroChina Southwest Oil & Gas Field Company) | Zhang, Fengxia (PetroChina Southwest Oil & Gas Field Company) | He, Yu (PetroChina Southwest Oil & Gas Field Company) | Xia, Ruochen (PetroChina Southwest Oil & Gas Field Company)
Abstract In the past decade, the operators and service companies are seeking an integration solution which combines engineering and geology. Since our drilling wells are becoming much more challenging than ever before, it requires the office engineer not only understanding well construction knowledge but also need learn more about geology to help them address the unexpected scenarios may happen to the wells. Then a novel solution should be provided to help engineers understanding their wells better and easier in engineering and geology aspects. The digital twin technology is used to generate a suppositional subsurface world which contains downhole schematic and nearby formation characteristics. This world is described in 3D modelling engineers could read all the information they need after dealt with a unique algorithm engine. In this digital twin subsurface world, the engineering information like well trajectory, casing program, BHA (bottom hole assembly) status, are combined with geology data like formation lithology, layer distribution and coring samples. Both drilling or completion engineers and geologist could get an intuitive awareness of current downhole scenarios and discuss in a more efficient way. The system has been deployed in a major operator in China this year and received lot of valuable feedback from end user. First of all, the system brings solid benefits to operator's supervisors and engineers to help them relate the engineering challenges with according geology information, in this way the judgement and decision are made more reliable and efficiently, also the solution or proposal could be provided more targeted and available. Beyond, the geology information from nearby wells in digital twin modelling could also provide an intuitional navigation or guidance to under-constructed wells avoid any possible tough layers via adjusting drilling parameters. This digital twin system breaks the barrier between well construction engineers and geologists, revealing a fictive downhole world which is based on the knowledge and insight of our industry, providing the engineers necessary information to support their judgement and assumption at very first time when they meet downhole problems. For example, drilling engineers would pay extra attention to control the ROP (rate of penetration) while drilling ahead to fault layer at the first time it is displayed in digital twin system, which prevent potential downhole accident and avoid related NPT (non-production time). The integration of engineering and geology is a must-do task for operators and service companies to improve their performance and reduce downhole risks. Also, it provides an interdisciplinary information to end user for their better awareness and understanding of their downhole asset. Not only help to avoid some possible downhole risks but also benefit on preventing damage reservoir by optimizing the well construction parameters.
Di, J. (CNPC Offshore Engineering Co Ltd) | Zhao, X. (PetroChina Investment Overseas Middle East Limited-Abu Dhabi) | Lv, J. (CNPC Offshore Engineering Co Ltd) | Rao, L. (PetroChina Investment Overseas Middle East Limited-Abu Dhabi)
Abstract For matured offshore oil field in Abu Dhabi, lots of wells need to be permanent abandonment. According to the regulations on offshore permanent well abandonment, the wellhead shall be cut from 4 m below the mudline. The purpose of this paper is to introduce an abrasive waterjet technology to solve the challenge so that cut two or three casings around seabed which is cemented together with a high efficiency method. Traditional operations for cutting multi-casing depend on milling cement and cutting single layer, which are inefficiency and time cost. Abrasive Waterjet technique utilize high water with abrasive material to cut multi-layer casing. This method does not limited to casing layer mount and size. The abrasive waterjet system is mainly composed of speed rotation control system, hydraulic anchoring system, cutting tools, ground supporting equipment, etc. The nozzle parameters were optimized by flow field simulation, and the corresponding tools were designed. The cutting tools includes several spray nozzles and transmit high pressure abrasive to casing surface to cutting. The cutting tools 360 degree rotation powered by speed rotation control system and fixed by hydraulic anchoring system. The abrasive waterjet is placed in cutting location in inner casing. A two-caisng cementing inner casing 339.7mm and outer casing 850mm together is used as an experimental target. In order to closer simulate the actual working conditions on site, inner casing has 150mm off-center. The abrasive waterjet was inside the target to cutting. The system connects to a pump with 70MPa and 0.9-1.0m/min flow rate. 40-60 mesh garnet is used as abrasive material. In order to simulate the cutting conditions on offshore site, the cutting tool is always submerged under the water during the test. After about 8 hours of experiments, the target cutting is successfully completed, and the cutting head and protective sleeve, hydraulic rotation speed control device and hydraulic anchoring device work smoothly, which proves that the abrasive jet cutting system has reasonable design and stable performance. The wear resistance of the nozzle during the experiment is analyzed. The nozzle does not change in the outlet diameter after 8 hours wear. Through this experimental research, it is proved that the reasonable selection of nozzle parameters and construction parameters can meet the overall cutting of eccentric multi-layer casing. This parameters can support for on-site construction parameter selection. If a traditional milling method to solve this problem, it usually takes several days. The advantages of this technology in time efficiency are proved. In addition, an offshore abandonment operation was applied by this technique which was conducted on a three-casing cemented casing. This paper will provide a novel method to solve the multi-casing cutting challenge for offshore well permanent abandonment. The abrasive jet cutting system design, tools and parameters feasibility of field application are verified. Compare to traditional method, it can greatly reduce the operation time and project cost.
Huang, Yi (CNOOC China Limited, Zhanjiang Branch, Zhanjiang 524057, China) | Liu, Hexing (CNOOC China Limited, Zhanjiang Branch, Zhanjiang 524057, China) | Liu, Zhiqin (CNOOC China Limited, Zhanjiang Branch, Zhanjiang 524057, China)
Abstract L2 formation of X Oilfield in western South China Sea is of characteristic of low porosity, low permeability and well controlled reserves, and long well interval, drainage area and controlled reserves can be significantly increased by adopting ultra-short radial radius drilling technology. Flexible drill pipe and drill bit was used in Well WZ-X1 to perform kick-off operation with only 2.4 m footage to increase inclination from 37 °to 87 °, and hold its inclination by drilling 60-62 m alongside reservoir with trajectory control margin of ±2°. This paper highlights the trajectory control technology with research of BHA, build-up and hold drill bit, and accurate calculation. During the field operation, drilling parameters were adjusted on the basis of formation variation and outstanding trajectory effect was accomplished and ultra-short radial radius trajectory control technology was achieved. This technology can solve the problem of trajectory control and extend horizontal section of reservoir. It can increase wellbore drainage area and well control reserves, providing technical reference for future operation.
Wu, Bohong (Research Institute of Petroleum Exploration & Development, PetroChina, Beijing, China) | Qiu, Ping (China University of Petroleum, Beijing, China) | Shi, Shuzhe (Research Institute of Petroleum Exploration & Development, PetroChina, Beijing, China) | Zhang, Yanna (Research Institute of Petroleum Exploration & Development, PetroChina, Beijing, China) | Huang, Xueqin (Research Institute of Petroleum Exploration & Development, PetroChina, Beijing, China) | Nie, Zhen (Research Institute of Petroleum Exploration & Development, PetroChina, Beijing, China)
Abstract In a Middle East oilfield, reservoirs are characterized by high temperature, high salinity, high CO2 / H2S content, and low pH, which leads to harsh corrosive environment. With development of the field, the increasing water cut and application of CO2-EOR technology have made tubulars face greater corrosion risk. Therefore, employing feasible anti-corrosion coating to corresponding part is one of the most effective technologies to mitigate downhole corrosion risk, reduce workover, and avoid potential HSE risk. Corrosion environment characteristics was thoroughly studied by reviewing production history, water chemistry, gas composition, downhole temperature and pressure, logging data, etc. Downhole corrosion condition was classified based on NACE standard RP0775-2005. Based on this, the field simulated corrosion tests were carried out on the self-healing coating in high-temperature and pressure autoclave. The self-healing coating was fabricated by loading slow-released MBT-LDH nanocomposites to the phenolic epoxy resin. For comparison, the similar experiment was also conducted on commercial phenolic epoxy coating and heavy-duty coating. The anti-corrosion performance and applicability of the coatings were characterized by SEM/EDS, FT-IR and EIS. Two main factors have been considered while evaluating the coating options, the first consideration is reliability and durability of the coating. If the coating is easily damaged during operation and transportation, its protective performance decreases after damage, which cannot be easily repaired again. The second consideration is the compatibility of the coating in a harsh downhole environment. Considering the above aspects, the self-healing coating, commercial phenolic epoxy coating and commercial heavy-duty were selected. After corrosion tests, a small amount of corrosion products can be observed on the commercial phenolic epoxy coating surface both in the simulated well head and bottom condition. There were no obvious morphology changes on the heavy-duty coating surface in both condition, however, chemical degradation of the coating was observed in well bottom condition. Notably, the self-healing coating appeared no peeling, bubbling and other defects in both conditions. There were corrosion products identified in the pre-destructed area of the coating, which attributed to the localized inhibition of the self-healing coating. This paper investigated the corrosion resistance coating technology, including coating selection evaluation, typical tubing thread area protection technique, coating chemical and physical property analysis and evaluation. The study also recommended coating applicability for the target reservoir. The results suggested that phenolic epoxy based self-healing coating show robust anti-corrosion performance and can be used in the downhole containing CO2 and H2S.
Chen, Qiang (RIPED, PetroChina Co. Ltd, Beijing, China) | Hao, Zhongxian (RIPED, PetroChina Co. Ltd, Beijing, China) | Huang, Shouzhi (RIPED, PetroChina Co. Ltd, Beijing, China) | Gao, Yang (RIPED, PetroChina Co. Ltd, Beijing, China) | Wei, Songbo (RIPED, PetroChina Co. Ltd, Beijing, China)
Shale oil had attracted worldwide attention due to its vast volume, according to statistics, technical recovery of shale oil worldwide exceeded 250billion ton, mostly located in America, Africa and north Asia. However shale oil was characterized by its high viscosity, deep reservoir location, posing threats to the operator, traditional rod-pump artificial lift was not a good choice due to the friction issue, How to walk out of those challenges were worth thinking, while rod free artificial lift methods had been field proven in the oilfield, its progress would give us some inspirations. In this paper, rod free artificial lift methods including downhole motivated reciprocating pump, centrifugal pump and progressing cavity pump were discussed, some technological highlights such as pulling and running electric cables, host SCADA system and production control algorism had been introduced in detail. Finally the efficacy of rodless artificial lift was analyzed from the perspective of investment
Han, Haochen. (CPET Beijing Petroleum Machinery Co., Ltd., Beijing, China / CNPC R&D, DIFC Company Limited, Dubai, UAE) | Wang, Bo. (CPET Beijing Petroleum Machinery Co., Ltd., Beijing, China) | Li, Bo. (CPET Beijing KEMBL Petroleum Technology Development Co., Ltd., Beijing, China) | Cheng, Tengfei. (CPET Beijing Petroleum Machinery Co., Ltd., Beijing, China) | Fengliu, Hui. (CNPC R&D, DIFC Company Limited, Dubai, UAE) | Zhang, Yao. (CPET Beijing Petroleum Machinery Co., Ltd., Beijing, China) | Chu, Fei. (CPET Beijing Petroleum Machinery Co., Ltd., Beijing, China)
Abstract In drilling operation, drilling NPT caused by top drive mechanical failure and high noisy and energy suffered a lot onsite. This paper introduces a top drive which utilizes a permanent magnet synchronous AC motor to drive the quill directly without a gearbox which can shorten drive chain. Meanwhile, its symmetrical and compact mechanical construction and shorter main and control cables obviously improve installation efficiency and effectively reduce the failure rate. We conducted research through structural design, motor efficiency and heat dissipation, and automation system upgrades to form a set of high-efficiency, high-performance direct drive top drive. Transmission structure aspect: design of direct-drive top drive structure, calculation and verification of main load bearing parts, analysis of top drive failure types and effects. Motor energy efficiency aspect: research on speed measurement method of permanent magnet direct drive motor, precise control method of permanent magnet direct drive motor, and closed phase change heat dissipation technology. Automation enhancement aspect: research on control system architecture, self-diagnosis system, One-click operating system. This study resulted in three research findings including synchronous permanent magnet motor design, One-Click operating system with self-diagnosis and efficient self-circulation heat dissipation technology. The new generation of direct-drive top drive can reduce current required by 100-200A and increase efficiency by 20-30% compared with asynchronous motor, while meeting the requirements of corresponding rated load, rated power, speed and continuous torque. It can realize quill rotation precision less than 1° under load and keep the speed fluctuation reduced from 10.6% to 1.1% by improving the motor dynamic response performance. The One-click control method realized by preset parameters can reduce the driller's repeated operation and visual judgment. The tripping efficiency can be increased by 11.9%, reducing the driller's operation complexity and improving drilling safety. The application of phase-change heat dissipation system can reduce ambient noise to 72dB without external circulating pump. At present, over 10 sets of this new equipment have been delivered and industrial applications have been launched in CNPC Dagang Oilfield, CNPC Weiyuan National Shale-Gas Demonstration Zone and Sinopec NiuYe Shale-Gas Demonstration Zone. Till now nearly 20 wells have been conduct with running trouble-free throughout. Intelligent direct drive top drive of synchronous permanent magnet motor with phase change heat dissipation can not only improve the top drive mechanical transmission efficiency and extend the service life of main components, but also can reduce energy consumption and improve the automation level of top drive, making the top drive further satisfy the high-demanded requirements in drilling operation. We believe that there will be a great demand in deep wells, ultra-deep wells and unconventional oil and gas resources exploitation, which has a broad application prospect and good economic and social benefits.
Wu, Bohong (Research Institute of Petroleum Exploration & Development, PetroChina) | Nie, Zhen (Research Institute of Petroleum Exploration & Development, PetroChina) | Li, Yong (Research Institute of Petroleum Exploration & Development, PetroChina) | Deng, Xili (Research Institute of Petroleum Exploration & Development, PetroChina) | Ma, Ruicheng (Research Institute of Petroleum Exploration & Development, PetroChina) | Xu, Jiacheng (Research Institute of Petroleum Exploration & Development, PetroChina)
Abstract Marginal reserves are an important play in future energy development. Based on the statistics of China National Petroleum Corporation (CNPC), the low permeability and unconventional reservoirs occupied 92% of newly found proven reserves in China. To overcome challenges such as poor reservoir conditions, weak natural energy, low displacement efficiency, and insufficient single well production, CNPC has conducted years of research and operation to cost-effectively develop China's marginal reserves. To develop the marginal fields economically, it is required to maximize single well production, recovery and reservoir sweep with minimum CAPEX and OPEX reasonably. The production enhancement is realized by 3 key technologies, namely, sweet spot identification, multi-layered 3D short spacing horizontal well pattern, and volumetric fracturing techniques. The cost reduction is achieved by the full life cycle practice of utilizing "large cluster, factory" well design and field operation, drilling prognosis optimization, integrated intelligent surface system, and unmanned operation. CNPC cost-effective development mode is practical and successful, marginal fields characterized with heterogeneous, multi-layered oil-bearing intervals with poor continuity are being economically developed in China. By comprehensive geological study, fit-for-purpose technologies application, and geoscience-to-engineering integration, the fracture control degree of horizontal wells increased from 60% to more than 90% based on micro-seismic events, stimulated reservoir volume (SRV) increased by 46.8%, average cumulative oil production per well is more than 100 times than original production in the field. Fast and early cash flow is realized by minimum production facilities. The average drilling cycle is shortened by 61%, the surface facility construction time is reduced by 65%, and the average single well investment is reduced by 42%.
Abstract The deep shale gas reservoir are high formation temperature and pore pressure in Sichuan Basin. Due to the unclear geomechanical characteristics of the reservoir, a large number of accidents occurred during the drilling operation. At the same time, the wellbore instability and frequent adjustment trajectory cause long drilling cycle, low drilling efficiency, and high drilling operation cost. To solve the above problems, the drilling mud weight is optimized based on the three-dimensional geomechanical research and by establishing the pore pressure, collapse pressure and fracture pressure (leakage pressure) models. The key technology of reducing drilling mud weight are used to significantly reduce the drilling mud loss. Field application shows that the mud weight is reduced from 2.15 g/cm to 1.87 g/cm, the average ROP increased by 44.1% from 8.4 m/h to 12.1 m/h, the average drilling operation cycle decreased by 40.7% from 54.2 days to 32.1 days, and the drilling performance and efficiency are significantly improved. The fine 3D geomechanical modeling technology has great promotion and reference significance for the performance and efficiency improvement of the deep shale gas horizontal well drilling operation in China.
Guo, H. J. (Drilling Mechanical Department, CNPC Engineering Technology R&D Company Limited, Beijing, China) | Zhou, Y. (Drilling Mechanical Department, CNPC Engineering Technology R&D Company Limited, Beijing, China) | Wang, B. D. (Drilling Mechanical Department, CNPC Engineering Technology R&D Company Limited, Beijing, China) | Zhang, Q. L. (Drilling Mechanical Department, CNPC Engineering Technology R&D Company Limited, Beijing, China) | Xu, B. G. (Drilling Mechanical Department, CNPC Engineering Technology R&D Company Limited, Beijing, China) | Jao, T. (Drilling Mechanical Department, CNPC Engineering Technology R&D Company Limited, Beijing, China) | Zhou, S. H. (Drilling Mechanical Department, CNPC Engineering Technology R&D Company Limited, Beijing, China)
Abstract Refracturing is a promising means to improve the output and estimated ultimate recovery of shale oil and gas resources, which is an efficient method to recover the productivity of low permeability old wells. Refracturing has achieved good results in the development of shale gas wells in North America, and has increased output and decreased the extraction cost significantly of shale gas resources. The disadvantage of unable to control the fracturing fluid accurately of the conventional temporary plugging diverting refracturing technologies like chemical particulates has been exposed in the applications. Wellbore reconstruction technology based on the solid expandable tubular (SET) was studied in this paper, which is a permanent plugging diverting refracturing technology with a high sealing effect and simple operation. Technical principles, tool structures and construction processes were analyzed and relative laboratory tests were conducted to verify the feasibility of this technology. Meanwhile, comparisons between expandable tubular technology and other refracturing technologies were developed to analyze the application prospect in shale oil and gas resources. The indoor tests indicated that wellbore reconstruction technology based on expandable tubular can plug the perforation on the casing effectively with certain sealing pressure, which showed that this technology can realize the wellbore reconstruction to create the wellbore conditions for the next fracturing work. Compared with other temporary plugging refracturing technologies, the expandable tubular technology can achieve accurate control of fracturing fluid and has a better effect of refracturing work. At the same time, it has the advantages of simple operation and big internal diameter compared to other wellbore reconstruction methods like casing plugging technology, which means that bigger displacement can be used and better effect can be achieved in the refracturing work. The conclusions obtained in this paper can promote the development of wellbore reconstruction technology based on expandable tubular, which provides a theoretical reference for the design of the refracturing work in shale oil and gas resources.