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Collaborating Authors
Results
- Well Completion > Hydraulic Fracturing (0.99)
- Reservoir Description and Dynamics > Reservoir Fluid Dynamics > Flow in porous media (0.99)
- Production and Well Operations > Well & Reservoir Surveillance and Monitoring (0.79)
- North America > United States > Texas (1.00)
- Europe (0.93)
- Research Report > New Finding (0.93)
- Overview (0.88)
- Geology > Geological Subdiscipline > Geomechanics (1.00)
- Geology > Rock Type > Sedimentary Rock > Carbonate Rock (0.68)
- Geology > Rock Type > Sedimentary Rock > Clastic Rock > Sandstone (0.47)
- Geophysics > Borehole Geophysics (1.00)
- Geophysics > Seismic Surveying > Seismic Modeling > Velocity Modeling (0.93)
- Well Completion > Hydraulic Fracturing (1.00)
- Reservoir Description and Dynamics > Unconventional and Complex Reservoirs > Shale gas (1.00)
- Reservoir Description and Dynamics > Storage Reservoir Engineering > CO2 capture and sequestration (1.00)
- (20 more...)
Dispersion and attenuation characteristics of obliquely incident SV wave in a fluid-saturated porous rock containing aligned penny-shaped fractures
Wang, Wenhao (China University of Petroleum (East China)) | Li, Shengqing (China University of Petroleum (East China), Laoshan National Laboratory) | Guo, Junxin (Guangdong Provincial Key Laboratory of Geophysical High-Resolution Imaging Technology, Southern University of Science and Technology) | Zhao, Long (China Oilfield Services Limited) | Guo, Shangjing (China Oilfield Services Limited) | Su, Yuanda (China University of Petroleum (East China), Laoshan National Laboratory) | Tang, Xiao-Ming (China University of Petroleum (East China), Laoshan National Laboratory)
Owing to the complex structural characteristics of aligned fractured rocks with a fluid-saturated porous background, many existing single-wave attenuation mechanism models cannot accurately characterize measuring multiband SV wave data. Moreover, the coupled effect of wave-induced fluid flow between fractures and the background (FB-WIFF) and elastic scattering (ES) from the fractures leads to ambiguity in the elastic response of the SV wave. Using Biots theory and mixed boundary constraints, we derived exact solutions to the scattering problem for a single penny-shaped fracture with an oblique incident SV wave. Furthermore, we developed a theoretical model for a set of aligned fractures by using Foldy's scheme. The numerical results showed that the FB-WIFF, ES of fractures, and their coupling effects were mainly responsible for wave dispersion and attenuation. The FB-WIFF occurs primarily in the low-frequency seismic exploration frequency band, whereas the ES of the fracture surface depends on the relationship between the wavelength and fracture size. In addition, we validated the accuracy and effectiveness of our model by comparing it with an existing interpolation approximation model and previous experimental measurements. The analysis results of this work can explain the acoustic response of SV wave experimental data in different frequency bands and theoretically support fracture detection and characterization.
- Geology > Geological Subdiscipline > Geomechanics (0.68)
- Geology > Structural Geology > Tectonics (0.67)
- Well Completion > Hydraulic Fracturing (1.00)
- Reservoir Description and Dynamics > Reservoir Characterization > Seismic processing and interpretation (1.00)
- Reservoir Description and Dynamics > Reservoir Fluid Dynamics > Flow in porous media (0.93)
Effects of Drilling Number and Distribution on Fracture Using the Pulse Plasma on Tight Sand Reservoir
Li, Zhaoxuan (Petroleum and Gas Engineering, LiaoNing Petrochemical University) | Wang, Shuo (Petroleum and Gas Engineering, LiaoNing Petrochemical University) | Pan, Yi (Petroleum and Gas Engineering, LiaoNing Petrochemical University (Corresponding author)) | Zhang, Rongqi (Petroleum and Gas Engineering, LiaoNing Petrochemical University) | Chen, Jiajun (Petroleum and Gas Engineering, LiaoNing Petrochemical University)
Petroleum and Gas Engineering, LiaoNing Petrochemical University Summary The permeability of unconventional reservoirs is extremely low, resulting in their drainage area being limited to tens of feet. Therefore, researchers have developed an effective stimulation technology that can be used in combination with conventional hydraulic fracturing, namely, pulsed plasma fracturing technology. Pulsed plasma fracturing technology is an efficient and environmentally friendly auxiliary hydraulic fracturing stimulation technology. However, most existing studies have focused only on the effect of pulsed plasma fracturing on single wells, ignoring the effect of the number and distribution of wells drilled on pulsed plasma fracturing. In this paper, pulsed plasma fracturing is studied by a self-built pulsed plasma experimental platform and nonlinear finite element software. First, the generation and propagation mechanism of shock wave, fracture type, and stress field analysis of rock mass in pulsed plasma fracturing technology are discussed. The double-well experiment was carried out by using the experimental platform, and the fracture law of fractures under different wellhead distribution conditions was obtained. In addition, a multiwell mathematical model is established by using the combination of the Euler method and Lagrange method to simulate the interaction between fluid and solid, that is, arbitrary Lagrangian Eulerian (ALE) multimaterial fluid-solid coupling method and the influence of drilling times and wellhead distribution on pulsed plasma fracturing is discussed. Stress analysis shows that the rock is mainly affected by ground stress, liquid column pressure, and shock wave pressure. The experimental results show that the discharge voltage is positively correlated with the shock wave pressure on the rock. The distribution of different wellheads affects the distribution and length of fractures. The double-well experiment makes the fractures easier to fracture. The simulation results show that the fracture length in the connection direction of the two wells is longer, and the fracture length in the vertical direction is shorter. This shows that the number and distribution of drilling affect the initiation and propagation of fractures. Introduction Nowadays, with the increasing demand for oil and gas resources, conventional oil fields have entered a period of exploitation attenuation (Asif and Muneer 2007; Li et al. 2017; Williamson and Esterhuyse 2020; Madon 2020).
- Research Report > Experimental Study (0.68)
- Research Report > New Finding (0.54)
- Geology > Geological Subdiscipline > Geomechanics (1.00)
- Geology > Rock Type > Sedimentary Rock > Clastic Rock > Sandstone (0.84)
- Energy > Oil & Gas > Upstream (1.00)
- Materials > Chemicals > Commodity Chemicals > Petrochemicals (0.34)
- Asia > China > Shandong > North China Basin > Shengli Field (0.99)
- Asia > China > Liaoning > Bohai Basin > Liaohe Basin > Liaohe Field (0.99)
- Asia > China > Henan > Gucheng Field (0.99)
- Asia > China > Hebei > Bohai Basin > Huabei Field (0.99)
- Well Completion > Hydraulic Fracturing (1.00)
- Reservoir Description and Dynamics > Reservoir Characterization > Exploration, development, structural geology (1.00)
- Reservoir Description and Dynamics > Reservoir Characterization > Reservoir geomechanics (0.93)
- Reservoir Description and Dynamics > Reservoir Fluid Dynamics > Flow in porous media (0.88)
Engineered Ultra-Low Invasion Loss Control Solution Allows Circulation, Ensuring Cement Placement and Zonal Isolation in Liner Cementing Jobs and Through Coiled Tubing – Case Studies
Fazal, Muhammad Adnan (Sprint Oil and Gas Services FZC) | Ahmad, Syed Hamza (Sprint Oil and Gas Services FZC) | Yousuf, Arif (Sprint Oil and Gas Services FZC) | Rehman, Aziz ur (Sprint Oil and Gas Services FZC) | Noor, Sameer Mustafa (Oil & Gas Development Company Limited) | Nazir, Irfan (Oil & Gas Development Company Limited)
Abstract The conventional loss cure techniques are largely reactive and include addition of coarse grade particle, fibrous material and other viscous pills that are lost into formation during loss cure attempts. Being highly invasive, these loss cure solutions block pore throats and line producing fractures causing considerable formation damage and loss of net asset value. Moreover, these techniques pose additional challenges while placing thru slim liners and coiled tubing (in rigless applications) due to elevated risk of getting the circulation ports plugged. Moreover, during the era of technological revolution and decarbonization, an effective and efficient solution aids to promote the practices producing low carbon emission. The proactive wellbore shielding loss cure is a particle size distribution-based LCM solution having excellent fluid loss properties and exhibiting low permeability barrier at the fluid-rock interface. The low permeable shielding effect offers less invasion across a broad range of pores (1microns to 4,000microns) and thereby protecting formation from any permanent impairment. The solution covers the wide range applications of loss cure throughout well life ensuring zonal isolation and saving significant rig time. Customized particle size distribution does allow LCM solution to be pumpable thru liner complying the allowable particle sizes (less than 1,000microns) and concentrations (upto 18 lbs/bbl) and for coiled tubing specialized applications with allowable particles size of 100 microns while maintaining rheological properties (Fluid Loss<50 ml/30 min, 5lbs/100ft2>Ty<10lbs/100ft2 & PV<90 cp). This paper demonstrates the working principle and practical applications of engineered solution for loss cure and successfully achieving zonal isolation in 7" liner being placed as pre-cement spacer in naturally fractured formation. The wellbore shielding pre-cement spacer ensured the cement rise above loss point thus achieving zonal isolation in partial to complete losses environment and helps in minimizing formation's impairment. The same approach was adopted to cure losses in rigless with coiled tubing in both carbonate and sandstone reservoirs for well killing and zonal isolation without plugging the CT BHA and circulation ports while complying design requirements.
- South America (0.68)
- Asia > Middle East (0.28)
- Well Drilling > Wellbore Design > Wellbore integrity (1.00)
- Well Drilling > Pressure Management > Well control (1.00)
- Well Drilling > Drilling Operations (1.00)
- (8 more...)
Stress Evolution and Permeability Enhancement Mechanism of Multistage Cavity Completion in Coalbed Methane Horizontal Wells
Yang, Ruiyue (National Key Laboratory of Petroleum Resources and Engineering, China University of Petroleum, Beijing (Corresponding author)) | Chen, Jianxiang (National Key Laboratory of Petroleum Resources and Engineering, China University of Petroleum, Beijing) | Qin, Xiaozhou (National Key Laboratory of Petroleum Resources and Engineering, China University of Petroleum, Beijing) | Huang, Zhongwei (National Key Laboratory of Petroleum Resources and Engineering, China University of Petroleum, Beijing) | Li, Gensheng (National Key Laboratory of Petroleum Resources and Engineering, China University of Petroleum, Beijing) | Liu, Liangliang (State Key Laboratory of Coal and Coalbed Methane Co-mining)
Summary Coalbed methane (CBM) is an important clean energy resource. However, low gas production rate, especially in areas where hydraulic fracturing is notoriously inefficient, is the major obstacle that restricts the commercial development of CBM. Multistage horizontal well cavity completion has been observed to be successful in improving gas production rates in the Zhengzhuang block, Qinshui Basin, China. It has resulted in rates that are 1.5 times higher than the average production level achieved through horizontal well hydraulic fracturing. However, the stimulation mechanisms and major factors determining completion efficiency are still poorly understood. In this paper, we established a numerical model using the finite discrete element method (FDEM) to compute the stress evolution and fracture-network patterns. The accuracy of the model has been confirmed by analytical and numerical solutions. Subsequently, a series of parametric studies were performed to quantitatively analyze the mechanisms of multistage cavities influencing the stress evolution and fracture geometries in CBM reservoirs. Finally, we investigated a field case in an actual horizontal well located at the Qinshui Basin, where 17 cavity stages were completed. This case study further shed light upon the well completion strategies and optimization decisions. Implications and suggestions were also provided for field treatments to enhance the completion efficiency. The results demonstrate that FDEM can provide new insights into cavity completion mechanisms by explicitly accounting for fracture and fragmentation process at the field scale. The complex-fracture networks originated from multistage cavities consist of cavity-induced shear fractures, tensile fractures, mixed-mode fractures, and activated multiscale natural fractures, which is the primary reason for enhanced permeability and the essential difference from hydraulic fracturing. Compared with a single cavity, the interactions among multiple cavities can further promote the fracture-network connectivity and thus enlarge the stress-relief area and fracture area substantially. The selections of cavity geometrical parameters, including spacing, length, diameter, and number, have significant impacts on stress evolution (both magnitude and stress-relief area) and fracture patterns (such as fracture-network geometry, interconnectivity, propagation direction, and area). Stress evolution and fracture patterns reproduced from a field case in the Qinshui Basin can provide critical learnings for the industry in designing horizontal well cavity completion schemes. The key findings of this study are expected to deliver fundamental and practical guidelines for the horizontal well cavity completion in CBM or other unconventional oil and gas exploitation.
- North America > Canada (1.00)
- Asia > China (1.00)
- North America > United States > Colorado (0.28)
- (2 more...)
- Geology > Geological Subdiscipline > Geomechanics (1.00)
- Geology > Rock Type > Sedimentary Rock > Organic-Rich Rock > Coal (0.93)
- Geophysics > Borehole Geophysics (0.46)
- Geophysics > Seismic Surveying (0.46)
- North America > United States > New Mexico > San Juan Basin > Fruitland Formation (0.99)
- North America > United States > Colorado > San Juan Basin (0.99)
- North America > United States > Arizona > San Juan Basin (0.99)
- (7 more...)
- Well Drilling > Drilling Operations > Directional drilling (1.00)
- Well Completion > Hydraulic Fracturing (1.00)
- Reservoir Description and Dynamics > Unconventional and Complex Reservoirs > Naturally-fractured reservoirs (1.00)
- (2 more...)
Numerical Analysis of Permeability Changes for Clogging and Microcracks Induced by the Invasion of Fracturing Fluid
Liu, Bailong (Institute of Fluid Science, Tohoku University (Corresponding author)) | Yang, Deyi (Institute of Fluid Science, Tohoku University) | Ito, Takatoshi (Institute of Fluid Science, Tohoku University)
Institute of Fluid Science, Tohoku University Summary Hydraulic fracturing can produce a main fracture and increase flow efficiency. It can also result in the invasion of fracturing fluid, which can produce clay swelling. The invasion can block the pores and throats in the porous media and damage matrix permeability, while it can also induce microcracks under certain conditions. This study developed a numerical model to evaluate the permeability change induced by the invasion. Both pore-throat clogging and microcracks are integrated into the model. The numerical model coupled a flow model based on the pore-scale network method (PNM), a solid model, and a permeability evaluation model. The solid model and permeability evaluation model are based on our microcrack performance model reported previously. We validated the flow model by analytical results and the coupled model by previous experiments of the soaking test. Simulation results show that the invasion can decrease the permeability for the clogging effect and increase the permeability for the microcrack generation. The generation of microcracks can greatly increase the permeability even with the clogging effect for clay swelling. Our simulation results indicated that rock properties can affect the effect of clogging and microcracks on permeability. This study provides an approach for the selection of fracturing fluid and the design of fracturing fluid flowback. This is crucial for the understanding of the invasion on permeability and can serve as a guide for fracturing operations.
- Research Report > New Finding (0.48)
- Research Report > Experimental Study (0.48)
- Geology > Geological Subdiscipline > Geomechanics (1.00)
- Geology > Mineral > Silicate > Phyllosilicate (0.59)
- Well Completion > Hydraulic Fracturing (1.00)
- Reservoir Description and Dynamics > Reservoir Fluid Dynamics > Flow in porous media (1.00)
Summary The heterogeneity of tight reservoirs, along with their complex geologic characteristics and the diverse completion practices used, presents challenges in developing accurate models to forecast the productivity for multifractured horizontal wells (MFHWs) completed in these reservoirs. This paper introduces a new early-time diagnostic tool that leverages early-time two-phase flowback data to forecast long-term productivity and evaluate completion efficiency. To achieve this, two novel models were developed. The first model, the water/oil-ratio model (WORM), uses a hybrid analytical and data-driven approach to describe the observed log-linear relationship between water/oil ratio (WOR) and load recovery (amount of fracturing water produced back after hydraulic fracturing operations) as an analogy to the log-linear relationship between the water/oil relative permeability ratio and water saturation. Next, a neural network is used to couple WORM parameters with key petrophysical properties to analyze the impact of fracture and formation properties on WOR performance, predict WOR as a function of load recovery, forecast ultimate load recovery, and estimate effective fracture volume and initial water saturation in fracture. The second model, the cumulative oil production model (COPM), is a data-driven model that predicts oil production as a function of load recovery during the matrix-dominated flow regime. The application of WORM and COPM on Niobrara and Codell formation wells showed that Codell wells generally exhibit better load recovery and larger effective fracture volume compared with Niobrara wells, but both formations exhibit similar oil recovery performance, indicating independent flow regimes within the effective fractures. The effective fracture volume estimated by WORM was validated against the estimated volume from recorded microseismic events. The results also showed that using the same completion practice to achieve a similar effective fracture volume in child wells does not necessarily lead to similar oil productivity. This paper introduces a holistic workflow that links early two-phase flowback data with well productivity and completion efficiency and is anticipated to aid petroleum engineers in optimizing hydraulic fracturing operations.
- North America > United States > Texas (0.93)
- North America > United States > Colorado (0.66)
- Research Report > New Finding (0.93)
- Research Report > Experimental Study (0.67)
- Geology > Geological Subdiscipline > Geomechanics (1.00)
- Geology > Geological Subdiscipline > Economic Geology > Petroleum Geology (0.41)
- North America > United States > Wyoming > DJ (Denver-Julesburg) Basin > Codell Formation (0.99)
- North America > United States > Texas > Anadarko Basin (0.99)
- North America > United States > Kansas > Anadarko Basin (0.99)
- (10 more...)
- Well Completion > Hydraulic Fracturing (1.00)
- Reservoir Description and Dynamics > Reservoir Fluid Dynamics > Flow in porous media (1.00)
- Reservoir Description and Dynamics > Improved and Enhanced Recovery > Waterflooding (1.00)
- (2 more...)
General Optimization Framework of Water Huff-n-Puff Based on Embedded Discrete Fracture Model Technology in Fractured Tight Oil Reservoir: A Case Study of Mazhong Reservoir in the Santanghu Basin in China
Xiang, Yangyue (School of Earth Resources, China University of Geosciences, Wuhan) | Wang, Lei (School of Earth Resources, China University of Geosciences, Wuhan (Corresponding author)) | Si, Bao (Tuha Oilfield Company, Petro China, Hami) | Zhu, Yongxian (Tuha Oilfield Company, Petro China, Hami) | Yu, Jiayi (Research Institute of Exploration and Development, Tuha Oilfield Company, Petro China, Hami) | Pan, Zhejun (Key Laboratory of Continental Shale Hydrocarbon Accumulation and Efficient Development, Ministry of Education, Northeast Petroleum University, Daqing)
Summary Water injection huff-n-puff (WHnP) is currently an important technology to improve the recovery of tight reservoirs. On the one hand, this technology can replenish the formation energy, and on the other hand, it can effectively replace the oil in a tight reservoir. In this paper, the effect of WHnP on cumulative oil production and oil increase rate is simulated and analyzed by comparing depleted development and WHnP scenarios, using numerical simulation methods. A field-scale numerical simulation was modeled based on typical fluid, reservoir, and fracture characteristics of Mazhong tight oil, coupled with geomechanical effects, stress sensitivity, and embedded discrete fractures. The result of different WHnP cycles is studied, and the limiting WHnP cycle is determined to be four cycles. The WHnP efficiency is compared for different permeability scales from 0.005 to 1 md, and it is determined that WHnP at a permeability of 0.01 md resulted in the largest production enhancement. Subsequently, sensitivity studies are conducted using an orthogonal experimental design for six uncertain parameters, including the WHnP cycle, production pressure difference, permeability, natural fracture density, hydraulic fracture half-length, and conductivity. The results show that throughput period and permeability are important parameters affecting cumulative oil production, and permeability and natural fracture density are important parameters affecting oil increase rate. In addition, contour plots of permeability and WHnP cycle, hydraulic fracture half-length, and conductivity are generated. Based on these plots, the optimal conditions with better enhanced recovery results in different WHnP scenarios can be easily determined. This study can better solve the problems encountered in WHnP of tight reservoirs and provide a theoretical basis for stable and efficient development.
- Research Report > New Finding (0.48)
- Research Report > Experimental Study (0.34)
- Geology > Geological Subdiscipline > Geomechanics (1.00)
- Geology > Geological Subdiscipline > Economic Geology > Petroleum Geology (0.42)
- Energy > Oil & Gas > Upstream (1.00)
- Water & Waste Management > Water Management > Lifecycle > Disposal/Injection (0.35)
- Well Completion > Hydraulic Fracturing (1.00)
- Reservoir Description and Dynamics > Unconventional and Complex Reservoirs > Naturally-fractured reservoirs (1.00)
- Reservoir Description and Dynamics > Reservoir Simulation (1.00)
- (2 more...)
Developed in the late 1940s, fracture stimulation, also known as hydraulic fracturing, is the practice of injecting a well with large amounts of frac fluids under high pressure in order to break the rocks. HOW DOES WELL FRACTURING WORK TO STIMULATE PRODUCTION? Stimulation techniques are used to encourage production to flow from the reservoir rocks. Hydrocarbons are located in the spaces between pores of reservoir rock. Production is achieved when these pore spaces are connected and permeability, or the ability to transmit fluids, is such that the hydrocarbons flow out of the rock and into the well.
- Well Completion > Hydraulic Fracturing (1.00)
- Reservoir Description and Dynamics > Reservoir Fluid Dynamics > Flow in porous media (0.40)
- Well Drilling > Wellbore Design > Wellbore integrity (0.32)
- Information Technology > Knowledge Management (0.40)
- Information Technology > Communications > Collaboration (0.40)