Article
Energy & Fuels
Xuwu Luo, Guancheng Jiang, Lele Yang
Summary: This study focused on typical fractured carbonate reservoirs in the Shunbei field, China, and investigated the multiscale reservoir space characteristics and core wettability of ultradeep fractured carbonate reservoirs. The results showed that the primary damage mechanisms of this reservoir are fluid sensitivity and liquid phase trapping. Abnormally low water saturation, mixed wettability, abundant clay minerals, and the fourth-order fracture network contribute to fluid sensitivity and liquid phase trapping damage.
GEOMECHANICS FOR ENERGY AND THE ENVIRONMENT
(2023)
Article
Energy & Fuels
Olatunji Olayiwola, Vu Nguyen, Opeyemi Bello, Ebuka Osunwoke, Boyun Guo, Catalin Teodoriu
Summary: This study analyzes the impact of salt in drilling fluid on fluid temperature distribution using a mathematical model and proposes a computational system for evaluating and optimizing drilling fluid system performance. The introduction of an adjustment factor allows the base model to accommodate changes in annular fluid composition during drilling in saline formations.
JOURNAL OF PETROLEUM EXPLORATION AND PRODUCTION TECHNOLOGY
(2022)
Article
Energy & Fuels
A. Falavand-Jozaei, E. Hajidavalloo, Y. Shekari, S. Ghobadpouri
Summary: The study investigated the prediction of bottom-hole pressure under underbalanced drilling conditions using a non-isothermal three-phase flow model considering geothermal effects. It found that factors such as viscous dissipation, heat from friction, and influx of oil and gas from reservoir significantly influence the distribution of fluid temperature in the wellbore, thereby affecting bottom-hole pressure.
PETROLEUM EXPLORATION AND DEVELOPMENT
(2022)
Article
Automation & Control Systems
Timm Strecker, Ulf Jakob F. Aarsnes
Summary: In this article, a feedback controller is proposed to stabilize the underbalanced drilling system, using only topside measurements and assuming unknown reservoir parameters. An observer estimates the distributed gas concentration, downhole pressure, and reservoir parameters, and the control inputs are constructed by designing target states. The results are demonstrated in simulations with an industry standard drift flux formulation.
IEEE TRANSACTIONS ON CONTROL SYSTEMS TECHNOLOGY
(2023)
Article
Multidisciplinary Sciences
Wen Zhou, Hanneke Paulssen
Summary: This study reveals the link between the passively recorded data of nearby passing trains and the fluctuations of the gas-water contact in the Groningen reservoir in The Netherlands. By analyzing the recorded train signals through deconvolution interferometry, the changes in inter-geophone P-wave travel times are detected. The observations indicate that the observed travel-time changes are related to fluctuations of the gas-water contact caused by pressure variations at a nearby well drilling.
SCIENTIFIC REPORTS
(2022)
Article
Engineering, Chemical
Zelong Xie, Liang Zhu, Shubo Bi, Hui Ji, Tianyi Wang, Mengting Huang, Hao Zhang, Huimei Wu
Summary: Wellbore leakage occurs usually in fractured formations with structural development. Real-time analysis of the leakage rate during the drilling process is crucial in understanding the leakage mechanism and rules in the field. This study improves the radial leakage model by considering the principles of fluid mechanics, using Herschel-Bulkley (H-B) drilling fluid, and simplifying various parameters. The results show that the deformation coefficient of the fracture index, fracture aperture, pressure difference, leakage rate, and cumulative leakage rate are positively correlated.
Review
Chemistry, Multidisciplinary
Nediljka Gaurina-Medimurec, Borivoje Pasic, Petar Mijic, Igor Medved
Summary: The text discusses the challenges faced by drilling engineers when drilling through naturally fractured reservoirs, as well as the methods to prevent loss of circulation and related consequences, such as blocking fractures and improving drilling and cementing technology.
APPLIED SCIENCES-BASEL
(2021)
Review
Polymer Science
Jingbin Yang, Jinsheng Sun, Yingrui Bai, Kaihe Lv, Guodong Zhang, Yuhong Li
Summary: This paper systematically summarizes the drilling fluid loss mechanism and model in fractured formation, analyzes the mechanism and main influencing factors to improve the formation's pressure-bearing capacity, and introduces the properties and interaction mechanism of various types of lost circulation materials.
Article
Energy & Fuels
Xiaolin Zhang, Binhua Dang, Xuecheng Wang, Shun Luo, Bugao Chen, Lihui Zheng
Summary: An innovative acid-soluble, solid-free drilling fluid system was developed to address the challenges of the carbonate reservoir in the northern Yishan slope of the Ordos Basin. Compared to the commonly used potassium ammonium based drilling fluid system, our novel solution showed significant improvements in density, solid content, acid-soluble rate, and reservoir permeability recovery. In practical field application, the use of this new drilling fluid system resulted in a 75.94% increase in gas production compared to nearby wells.
Article
Environmental Sciences
Qiang Li, Fuling Wang, Yanling Wang, Chang Zhou, Jiashuo Chen, Kobina Forson, Rufeng Miao, Yingjie Su, Jinyan Zhang
Summary: The objective of this research is to study the influence of filtrate reducer and reservoir characteristics on the filtration reduction of drilling fluid during drilling and to reveal the mechanism behind it. The results show that a synthetic filtrate reducer can significantly reduce the filtration coefficient compared to a commercial filtrate reducer. The filtration coefficient of drilling fluid constructed from the synthetic filtrate reducer is much lower than that of the commercial filtrate reducer, indicating a weaker filtration capacity. Increasing reservoir temperature and shear rate also increase the filtration coefficient of drilling fluid, while low temperature and shear rate are recommended for improving filtration capacity. Therefore, it is important to choose the appropriate type and content of filtrate reducer during drilling and avoid increasing reservoir temperature and shear rate.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2023)
Review
Chemistry, Analytical
Tawfik A. Saleh
Summary: This review discusses the analysis methods used for evaluating the inhibitors and properties of drilling fluids, including various tests such as capillary suction time, bulk hardness, and linear swell meter. The review proves to be a valuable reference for researchers and the industrial sector.
TRAC-TRENDS IN ANALYTICAL CHEMISTRY
(2022)
Article
Engineering, Geological
Zhiheng Chen, Guan Rong, Junsong Quan, Lida Xu
Summary: This paper presents a laboratory simulation of the core drilling process under high in situ stress conditions. The study quantitatively evaluates the sampling damage from macro and micro perspectives using mechanics tests and microscopic observations. The results show that the structure of the core is significantly changed by the sampling damage, and the uniaxial compressive strength and Brazilian tensile strength of the cores are reduced compared to the undamaged rock. Microstructural observations reveal a higher crack density in the cores drilled at high sampling confining pressure.
Article
Energy & Fuels
Ke Xu, Hui Zhang, Zhizhen Zhang, Guoqing Yin, Xiaoji Shang, Zhimin Wang, Haiying Wang, Fang Yuan, Ziwei Qian, Shujun Lai
Summary: This paper investigates the coupling effect of in situ stress and fluid pore pressure during hydraulic fracturing and gas fracturing in heterogeneous fractured reservoirs. A coupled fluid-solid-damage mathematical model is established and numerical simulations are conducted. The results show that continuous injection of nitrogen or water increases pore pressure and leads to rock damage and increased porosity. The damage area and length for nitrogen fracturing are larger than hydraulic fracturing, and the changes in pore pressure, permeability, and porosity are consistent with the damage area. The damage evolution during nitrogen fracturing is less affected by in situ stress and matrix permeability compared to hydraulic fracturing.
ENERGY SCIENCE & ENGINEERING
(2023)
Article
Engineering, Civil
Xiaoqi Zhang, Pan Liu, Maoyuan Feng, Chong-Yu Xu, Lei Cheng, Yu Gong
Summary: The joint design and operation of multi-reservoir systems is a vital issue in reservoir management. Existing studies focus on optimizing schemes, but neglect the mutual feedback mechanism between reservoirs' flood control capacities. This paper proposes a joint optimization method considering conditional value-at-risk and applies it to the Ankang-Danjiangkou Cascade Reservoirs in China. The findings provide insights into the relationship between flood storage values and the overall multi-reservoir system.
JOURNAL OF HYDROLOGY
(2022)
Article
Energy & Fuels
Xu Zhao, Qiushi Dai, Yi Pan, Shuangchun Yang, Wakam Fogaing Marcellin, Wei Li, Haiyan Zhang
Summary: This paper developed a new water-based drilling fluid system for unconsolidated sandstone reservoirs. The system's formula was optimized based on the characteristics of the formation and properties such as rheology and filter loss. The experimental results showed that the drilling fluid system effectively cleaned the borehole and had good antipollution properties.
ENERGY SOURCES PART A-RECOVERY UTILIZATION AND ENVIRONMENTAL EFFECTS
(2022)