Zhang, Wei

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.

OnePetro

doi: 10.2118/214625-MS

SPE

SPE-214625-MS

SPE/IADC Middle East Drilling Technology Conference and Exhibition

Country: Asia > China (0.48)

Genre: Overview (0.47)

Industry: Energy > Oil & Gas > Upstream (1.00)

Oilfield Places:

Asia > China > Sichuan > Sichuan Basin > Southwest Field > Longwangmiao Formation (0.99)
North America > United States > South Dakota > Williston Basin > Bakken Shale Formation (0.98)
North America > United States > North Dakota > Williston Basin > Bakken Shale Formation (0.98)
North America > United States > Montana > Williston Basin > Bakken Shale Formation (0.98)

SPE Disciplines:

Well Drilling > Drilling Operations > Drilling optimization (0.67)
Reservoir Description and Dynamics > Reservoir Characterization > Exploration, development, structural geology (0.49)
Data Science & Engineering Analytics > Information Management and Systems > Artificial intelligence (0.47)

Technology:

Information Technology > Artificial Intelligence (0.69)
Information Technology > Data Science (0.47)

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Intelligent Wireline Formation Tester Evaluation of Low-Permeability and Low-Resistivity-Contrast Formation

OnePetroMay, 2023

Abstract Exploration and development drilling in offshore China is extending to Paleogene formations that are characterized by low-resistivity-contrast and low-permeability rocks. These formations have become a focus for increasing reserves and production. During exploration activities, these low-resistivity, low-formation-contrast formations have been critical and challenging for formation evaluation because the geological structure and lithology are more complex than in previously discovered fields. Differentiating hydrocarbon from water using petrophysical interpretation has a large uncertainty in these formations. Confirming the fluid type using conventional formation testing technology has been extremely challenging because the produced fluid is mainly mud filtrate, which is no use for fluid confirmation. A new-generation intelligent wireline formation testing platform consisting of a focused radial probe inlet and a dual flowline with dual downhole pumps to enable flexible focused sampling was applied to three appraisal wells in offshore China. Given the larger flow area of the probe system, flow tests could be conducted in as low as 0.004-md/cP mobility zones (the tightest on record), and fluid identification could be performed in-situ while the fluid flowed through a group of sensors. Previous formation testing in these formations had been challenged because the water-based mud system caused suspension of solid particles (debris and mud solids). Filter and standoff accessories available with the intelligent wireline formation platform enabled designing a fit-for-purpose approach to overcome this challenge in a short time. This dedicated design resulted in increased efficiency in water sampling compared to previous testing done by the operator. Clean water resistivity, measured in situ, can now be applied to this new exploration block to recalculate the water saturation for reserve estimation. Whereas previous gas-water transition zone sampling was challenging because high water-based mud filtrate fractions masked the presence of formation water and formation hydrocarbon, the radial probe, combined with state-of-the-art resistivity measurements, allowed identification of gas and the measurement of formation water resistivity in a multiphase flow environment. The formation testing of these low-resistivity-contrast and low-permeability formations enabled acquisition of a 2% contaminated formation water sample in 140 minutes with formation mobility of 1 md/cP. The gas-water zone was confirmed from a dual flowline resistivity measurement and a hydrocarbon show in mobility of 1.4 md/cP.

OnePetro

doi: 10.4043/32269-MS

OTC

OTC-32269-MS

Offshore Technology Conference

Country:

Asia > China (0.70)
North America > United States > Texas (0.28)

Geologic Time: Phanerozoic > Cenozoic (0.67)

Industry: Energy > Oil & Gas > Upstream (1.00)

Oilfield Places:

Asia > China > South China Sea > Zhujiangkou Basin (0.99)
Asia > Taiwan > South China Sea (0.95)

SPE Disciplines:

Reservoir Description and Dynamics > Reservoir Fluid Dynamics > Flow in porous media (1.00)
Reservoir Description and Dynamics > Formation Evaluation & Management > Open hole/cased hole log analysis (1.00)
Reservoir Description and Dynamics > Formation Evaluation & Management > Formation test analysis (e.g., wireline, LWD) (1.00)

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Abstract Experimental methods for core plug analysis are widely used to measure formation permeability under steady-state flow or unsteady state flow conditions, which provides important geoscience information on formation properties. However, typical laboratory techniques hardly reproduce the two-phase water and hydrocarbon storage and transport conditions that formation is subject to in reality. Accordingly, we presented an integrated experimental core analysis method for permeability measurement, which better reproduces these two-phase conditions. The proposed experimental method consists of two-phase fluid initialization and production test, during which the gas rate, liquid rate, and inlet/outlet pressure of the core plug are recorded simultaneously. After constructing with uniform distribution of gas and liquid, the core sample is transformed into a two-phase production process under the conditions of variable rate and sealed boundary. Rate transient analysis is performed to estimate formation permeability with the gathered two-phase rate decline and pressure data. A two-phase diagnostic plot and specialty plot are introduced to identify flow regimes and extract permeability from the slope of a straight line during the experimental data analysis. In this paper, commercial software is used to generate synthetic data for the production test of a core plug. The simulation of two-phase fluid initialization and production tests were conducted on core plugs. The simulation results show a unit-slope straight line on the generated diagnostic plot, which indicates a clear boundary-dominated flow (BDF) regime. By performing a straight-line analysis, we calculated the permeability of the core plug with the slope of straight-line period on specialty plot. The good match of the calculated permeability with the reference value confirms the accuracy of the proposed experimental method with the relative error less than 10%. In addition, the proposed two-phase core analysis method can enormously accelerate test-time, as the permeability of selected rock sample can be estimated in less than 10 minutes. Instead of measuring permeability only under the condition of single phase flow, this paper presents a laboratory technique that combines the experiment of small-diameter core production test under two-phase flow with rate transient analysis method. Unlike prior experimental techniques, the proposed method reproduces the more realistic condition of two-phase flow in the formation during permeability measurement. The two-phase core analysis method achieves the objective of accurate and fast characterization of formation permeability, which is a more "apples to apples" comparison between the fluid flow in the actual reservoir and the core plug.

OnePetro

doi: 10.4043/32249-MS

OTC

OTC-32249-MS

Offshore Technology Conference

Country:

North America > United States > Texas (0.28)
Europe > Norway > Norwegian Sea (0.24)

Genre:

Research Report > New Finding (0.48)
Research Report > Experimental Study (0.34)

Industry: Energy > Oil & Gas > Upstream (1.00)

Oilfield Places:

Asia > China > Sichuan > Sichuan Basin (0.99)
Asia > China > Shanxi > Ordos Basin (0.99)
Asia > China > Shaanxi > Ordos Basin (0.99)
Asia > China > Gansu > Ordos Basin (0.99)

SPE Disciplines:

Reservoir Description and Dynamics > Reservoir Fluid Dynamics > Flow in porous media (1.00)
Reservoir Description and Dynamics > Formation Evaluation & Management (1.00)

Technology: Information Technology > Modeling & Simulation (0.48)

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Characterization of Tight Sandstone Reservoir Pore Structure and Validity from Geophysical Logging Data by Using Deep Learning Method

Li, Gaoren (1. Research Institute of Exploration & Development, PetroChina Changqing Oilfield) | Zhang, Wei (2. National Engineering Laboratory of Exploration and Development of Low Permeability Oil and Gas Fields, PetroChina Changqing Oilfield) | Liu, Die (Shenzhen Operating Company of Well-Tech Department, China Oilfield Services Ltd.) | Li, Jing (1. Research Institute of Exploration & Development, PetroChina Changqing Oilfield) | Li, Cheng (2. National Engineering Laboratory of Exploration and Development of Low Permeability Oil and Gas Fields, PetroChina Changqing Oilfield) | Li, Jiaqi (Research Institute of Geophysics, Research Institute of Exploration and Development, PetroChina Xingjiang Oilfield) | Xiao, Liang (1. Research Institute of Exploration & Development, PetroChina Changqing Oilfield)

OnePetroMarch, 2023

Abstract Pore structure described the macroscopic pore size and microscopic pore connectivity. It heavily determined formation quality and seepage capacity, and thus associated with permeability. Generally, ultra-low permeability to tight sandstone reservoirs were always affected by complicated pore structure and strong heterogeneity. Characterizing pore structure was of great importance in improving tight sandstone reservoir evaluation and validity prediction. Nuclear magnetic resonance (NMR) logging was considered to be valuable in pore structure prediction only in exploration wells because plenty of NMR logging data was acquired in key wells. However, methods that established in exploration wells cannot be directly extended into development wells due to the limitation of quantity of NMR data. In addition, NMR logging was only usable in pore structure characterization in water saturated layers, it cannot be directly used in hydrocarbon-bearing reservoirs. In this study, to establish a widely applicable pore structure characterization method that can be used not only in exploration wells, but also available in development wells to improve formation validity evaluation and high-quality formation identification in Triassic Chang 8 Formation of Shunning Region, Eastern Ordos Basin, we established a technique to synthetize pseudo-Pc curve from geophysical logging data by using deep learning method. This technique was raised based on the morphological feature analysis of mercury injection capillary pressure curves. We found that the applied mercury injection pressures were the same for all core samples during mercury injection experiments, the pore structure difference for all core samples was determined by injected mercury content (SHg) under the same Pc. Hence, once we predicted mercury content under every Pc, pseudo-Pc curve can be synthetized by combining predicted mercury content and known Pc. Constructing pseudo-Pc curve was translated as predicting mercury content. To establish a reasonable model that can be used in development wells, where only conventional logging data was available, we analyzed relationships among mercury contents under every mercury injection pressure and geophysical logging data. This analysis was raised based on heat map of decision tree technique, and the experimental data of 115 core samples that drilled from Triassic Chang 8 Formation in Shunning Region was used. Finally, we found that SHg under 15 capillary pressure was heavily related to porosity and deep and shallow resistivity. Based on this perfect relationship, we established a model to predict 15SHg from porosity and deep and shallow resistivity by using deep learning method of XGBoost. In this deep learning method, 92 clusters of core analysis data (accounting for 80.0% of the total), were used as training samples, and the rest 20.0% was retained as samples for verification. Meanwhile, relationship between SHgs under two adjacent mercury injection pressures was also closely related. Hence, after SHg under 15 Pc was predicted from conventional logging data, the other SHgs can be calculated by using step iterative method. In addition, considering the used input porosity in XGBoost was also difficult to be estimated based on statistical method, neutron, density, interval transit time (Δt) and delta natural gamma ray (ΔGR) were chosen as input parameters, and XGBoost was used to predict porosity from well logging data. Based on predicted porosity and deep and shallow resistivity, pseudo-Pc curves were consecutively synthetized to characterize pore structure of tight Chang 8 sandstone reservoirs. Meanwhile, pore throat radius distribution, and pore structure evaluation parameters were also calculated, comparison of predicted pore structure evaluation parameters and core derived results illustrated that calculation accuracy reached to 86.4%. In addition, we determined two pore throat radius cutoffs to classify pore throat radius into three parts, which represented small, intermediate and large pore throat sizes, separately. The relative contents of each type of pore throat sizes were calculated, separately. A parameter of formation validity indication was raised to evaluate formation pore structure. Relationship between formation validity indication and daily liquid production per meter was established, and formations were classified into three types. The first and second types of formations were effective formations that contained substantial hydrocarbon production capacity, and the third type of formation was dry. Our raised method and technique were well used to improve tight reservoirs characterization and evaluation in Chang 8 Formation of Shunning Region, and it would also be valuable in indicating the distribution of effective tight sandstones for formations with similar properties.

OnePetro

doi: 10.2118/214124-MS

SPE

SPE-214124-MS

Gas & Oil Technology Showcase and Conference

Country:

Asia > China > Shanxi (0.35)
Asia > China > Shaanxi (0.35)
Asia > China > Gansu (0.35)

Genre: Research Report > Experimental Study (0.34)

Geologic Time: Phanerozoic > Mesozoic > Triassic (0.45)

Geophysics: Geophysics > Seismic Surveying (0.49)

Industry: Energy > Oil & Gas > Upstream (1.00)

Oilfield Places:

North America > United States > Louisiana > China Field (0.99)
Asia > China > Xinjiang Uyghur Autonomous Region > Junggar Basin > Xingjiang Field > Lucaogou Formation (0.99)
Asia > China > Sichuan > Sichuan Basin > Puguang Field (0.99)
(8 more...)

SPE Disciplines: Reservoir Description and Dynamics > Formation Evaluation & Management > Open hole/cased hole log analysis (1.00)

Technology: Information Technology > Artificial Intelligence > Machine Learning > Neural Networks > Deep Learning (1.00)

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Scaling Equations for Benchtop Laboratory Simulator of Wellbore Hydraulics

Alarfaj, Mohammed Nabil (The Pennsylvania State University) | Zhang, Wei (The Pennsylvania State University) | Mehrabian, Amin (The Pennsylvania State University)

OnePetroOctober, 2022

Abstract Determining frictional pressure losses along a wellbore annulus is the key to estimation of the wellbore equivalent circulating density. Flow-loop experiments are often used at smaller scales of flow to measure the frictional pressure losses. However, a complete set of scaling equations between the measured pressure drop in a flow loop device and the one occurring in the wellbore has not been reported in the literature. This study applies dimensional analysis to make such connection while accounting for drill pipe rotation, eccentricity, and cuttings load in the annular flow of power-law drilling fluids. Simultaneous application of geometric, kinematic, dynamic, and rheological similarities allows for developing direct relations between the operational and flow quantities at the laboratory and wellbore scales of flow. For this purpose, the pertinent dimensionless groups are identified and set equal between the two flow scales. Results indicate that scaling the two-phase flow of drilling fluid and cuttings entails nine (9) dimensionless groups. The obtained scaling equations provide the required volumetric rate of fluid and particles, the inner pipe rotation speed, as well as the fluid rheology and other design parameters of the flow-loop device to establish the full similitude with the corresponding wellbore hydraulics. In particular, the Reynolds number of cuttings necessitates introducing a constraint on the rheology of fluid to be used in the laboratory flow loop. Once all scaling requirements of the considered similitude are applied, the pressure gradient along the wellbore annulus can be obtained directly in terms of the measured pressure drop in the laboratory flow loop.

OnePetro

doi: 10.2118/211886-MS

SPE

SPE-211886-MS

SPE Eastern Regional Meeting

Country: North America > United States (0.93)

Industry: Energy > Oil & Gas > Upstream (1.00)

SPE Disciplines:

Well Drilling > Drilling Operations (1.00)
Production and Well Operations > Well & Reservoir Surveillance and Monitoring > Production logging (1.00)

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Elastic Characterization of Shale at Microscale: A Comparison between Modulus Mapping, PeakForce Quantitative Nanomechanical Mapping, and Contact Resonance Method

Zhao, Junliang (Shenzhen Key Laboratory of Natural Gas Hydrates, Southern University of Science and Technology) | Zhang, Wei (Peking University) | Zhang, Dongxiao (Shenzhen Key Laboratory of Natural Gas Hydrates, Southern University of Science and Technology (Corresponding author))

OnePetroOctober, 2022

Summary Because of the extremely high resolution and little damage to the sample, micromechanical mapping methods have been widely used for elastic characterization of shale at microscale. However, few studies have investigated connections and differences among commonly used micromechanical mapping methods. The influencing factors of micromechanical tests, such as sample preparation, experimental setup, and data processing, have not yet been sufficiently discussed. In the presented paper, three representative micromechanical mapping methods, including modulus mapping (MM), PeakForce quantitative nanomechanical mapping (PFQNM), and contact resonance (CR) method, were systematically compared from theory to application. The fundamental principles of the three methods were introduced, and connections in theoretical background were discussed. A shale sample from the Yanchang Formation in the Ordos Basin was selected for elastic characterization. Mechanical tests were performed on a fixed area on the sample surface by using different methods. The modulus distribution images obtained by the three methods intuitively exhibited microheterogeneity in shale. The influences of scanning frequency, peak force frequency, and force setpoint were analyzed based on the test results. The comparison of the contact area revealed that MM possessed the lowest spatial resolution with the experimental setup, and the CR method was less sensitive to the surface condition than PFQNM. The effectiveness of the data processing method was demonstrated through scale dependency analysis, and the limitations of the test methods were discussed. This work may contribute to improved understanding and selection of micromechanical mapping methods and experimental design of elastic characterization of shale. Introduction The shale oil/gas revolution has transformed traditional knowledge in the oil industry and influenced the worldwide energy structure (Zou et al. 2020; Looney 2020). Creating complex fracture networks via hydraulic fracturing and horizontal wells has constituted an efficient approach to large-scale development of shale reservoirs. The study of the mechanical performance of shale is of great significance for the evaluation of fracability and the design of fracturing plans (Jin et al. 2015; Li and Zhang 2017). As a kind of natural composite material, shale rock consists of various inorganic minerals and organic matter (Liu et al. 2018).

OnePetro

doi: 10.2118/209795-PA

SPE

SPE-209795-PA

SPE Journal

Country:

Asia > China (0.88)
North America > United States > Texas (0.46)

Genre: Research Report (0.34)

Industry: Energy > Oil & Gas > Upstream (1.00)

Oilfield Places:

North America > United States > Texas > Fort Worth Basin > Barnett Shale Formation (0.99)
North America > United States > South Dakota > Williston Basin > Bakken Shale Formation (0.99)
North America > United States > Oklahoma > Anadarko Basin > Cana Woodford Shale Formation (0.99)
(7 more...)

SPE Disciplines:

Well Completion > Hydraulic Fracturing (1.00)
Reservoir Description and Dynamics > Unconventional and Complex Reservoirs > Shale gas (1.00)
Reservoir Description and Dynamics > Reservoir Characterization (1.00)

Technology: Information Technology (1.00)

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The Positive Effect of Geomechanics on Adsorption and Transport Processes During Co2 Huff-N-Puff in Organic Shale

Zhang, Wei (Pennsylvania State University) | Mehrabian, Amin (Pennsylvania State University)

OnePetroOctober, 2022

Abstract A thermodynamically rigorous constitutive model is used to describe the full coupling among the nonlinear processes of transport, sorption, and solid deformation in organic shale where the pore fluid is the binary mixture of carbon dioxide and methane. The constitutive model is utilized in a numerical solution that simulates injection of carbon dioxide in shale before producing carbon dioxide and methane from the same. The solution considers advection and diffusion as viable mechanisms of pore fluid transport where the latter comprises molecular, Knudsen, and surface diffusion in ultralow permeability shale. Results indicate that complete or partial exclusion of the coupling between sorption and solid phase deformation from the solution would result in underestimation of carbon dioxide storage capacity and natural gas recovery factor of the rock. In this aspect, sorption-induced deformation and strain-induced changes in gas sorption capacities are all conducive to both outcomes.

OnePetro

doi: 10.2118/210189-MS

SPE

SPE-210189-MS

SPE Annual Technical Conference and Exhibition

Country: North America > United States > Texas (0.46)

Industry: Energy > Oil & Gas > Upstream (1.00)

Oilfield Places: North America > United States > Gulf of Mexico > Central GOM > East Gulf Coast Tertiary Basin > Green Canyon > Block 237 > Green Canyon 237 Field > Wang Well (0.93)

SPE Disciplines:

Reservoir Description and Dynamics > Improved and Enhanced Recovery > Thermal methods (1.00)
Reservoir Description and Dynamics > Improved and Enhanced Recovery > Chemical flooding methods (1.00)

Technology: Information Technology (0.93)

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Comparative Study on Predicting Ship Maneuvering in Waves Using a Quasi-Steady Method and a Time Domain Approach

Zhang, Wei (Harbin Institute of Technology (Weihai)) | Cheng, Jie (Harbin Institute of Technology (Weihai)) | Li, Xuan (Harbin Institute of Technology (Weihai)) | He, Guanghua (Harbin Institute of Technology (Weihai))

OnePetroSeptember, 2022

_ Numerical prediction of ship maneuvering in waves was considered in this article. The wave drift loads, computed using the potential flow theory, were added into the mathematical modeling group (MMG) equations to account for the effect of waves on the ship maneuvering. Two numerical methods were tested for dealing with the coupled maneuvering-seakeeping problem, namely a time domain approach and a quasi-steady method. For the former approach, a time domain seakeeping computation was conducted that parallels to the maneuvering simulation. For the later one, it is assumed that at each time of the maneuvering process, the wave-ship interaction is in a time harmonic status and, therefore, the wave drift loads could be evaluated using a frequency domain computation. Turning maneuvers of the S-175 container ship in regular waves were numerically tested. The results of the quasi-steady method and the time domain approach show good agreements, which proved the validity of the quasi-steady assumption. The wave drift loads during the turning process were also presented, demonstrating the significant effect of the added resistance on the maneuvering prediction, in contrast to the less remarkable effects of the lateral wave drift force and the wave drift yaw moment. Introduction Ship maneuverability is typically predicted under calm water condition. This provides valuable information at the ship design stage. However, an actual seagoing ship usually maneuvers in waves. To reliably assess a ship’s navigation safety and total performance in a seaway, it is deemed important to understand the maneuvering behavior of a ship in waves. Indeed, ship maneuverability in waves has been increasingly investigated in recent years. Although the physical experiment is still regarded as the most reliable way to investigate ship maneuverability in waves, there are more and more studies providing practical mathematical models of ship maneuvering prediction. Generally, a mathematical model that is suitable for investigating the maneuvering of a ship in waves has to encapsulate the traditional theories of calm water maneuvering and forward-speed seakeeping.

OnePetro

doi: 10.5957/JOSR.06210021

SNAME

SNAME-JSR-06210021

Journal of Ship Research

Computation, equation, Journal, maneuver, maneuvering, maneuvering prediction, maneuvering simulation, marine transportation, Ocean Engineering, prediction, quasi-steady assumption, resistance, ship, ship maneuvering, ship research, Simulation, trajectory

Country:

Europe (0.67)
North America > United States > California (0.28)

Industry: Transportation > Marine (0.68)

SPE Disciplines:

Data Science & Engineering Analytics > Information Management and Systems (0.67)
Reservoir Description and Dynamics (0.47)

Technology: Information Technology (0.88)

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Effect of Crude Viscosity to Nuclear Magnetic Resonance (NMR) Responses in Different Types of Reservoirs: An Experimental Study

Zhang, Wei (Shenzhen Operating Company of Well-Tech Department, China Oilfield Services Co. LTD (COSL)) | Zhang, Ping (Shenzhen Operating Company of Well-Tech Department, China Oilfield Services Co. LTD (COSL)) | Li, Yi (Shenzhen Operating Company of Well-Tech Department, China Oilfield Services Co. LTD (COSL)) | Xiao, Liang (China University of Geosciences, Beijing)

OnePetroSeptember, 2022

Abstract Pore structure evaluation was of great importance in improving reservoirs characterization and validity prediction, especially in unconventional reservoirs. The nuclear magnetic resonance (NMR) log was considered to be advantageous in formation pore structure characterization, and many methods had been proposed to evaluate pore structure by using NMR log. However, NMR log can only be used to characterize rock pore structure under fully water saturation due to the domination of surface relaxation. In hydrocarbon-bearing formation, pore structure would be over or underestimated because of the effect of viscosity to the shape of NMR T2 spectrum. In this study, to understand the effect of saturated hydrocarbon to NMR responses, 20 core samples, which were separately drilled from ultra-tight, low permeability and conventional sandstone reservoirs, were applied for laboratory NMR experimental measurements under four saturation conditions. These four saturation conditions included irreducible water saturation, fully water saturated, oil saturated and residual oil. To quantize the effect of crude oil viscosity to NMR T2 spectra, underground oil was collected and processed in laboratory to simulate the used oil with 3 different viscosities in the NMR experiment. NMR experiments under residual oil saturation was used to simulate field NMR log due to shallow invasion radius of field NMR tool. Experimental results illustrated that NMR T2 distributions were heavily affected by crude oil viscosity. For core samples drilled from low permeability sandstone reservoirs, and saturated with light oil, NMR T2 spectra all exhibited as bimodal distributions, even if they were unimodal under fully water saturation. The shapes and locations of the left spectra (reflecting micro to small pore size) were similar with those of irreducible water. However, the shapes and locations of the right spectra (reflecting free fluids) were predominantly determined by the property of used oil in the experiments, and they were similar with the bulk relaxation T2 distributions of oil. In this case, pore structure would be overestimated if field NMR log was directly used for pore structure characterization. Comparing with NMR T2 distributions acquired from core samples with high porosity and permeability, and fully water saturated, the morphology of T2 spectra hardly changes after the pore spaces saturated with light oil. However, once the viscosity of saturated oil increased, the location of the right peak moved to the left, and they still exhibited similar position with the bulkrelaxationT2 distributions of saturated oil. Under extreme conditions the NMR T2 spectra of free fluids overlapped with those of irreducible water once the viscosity of saturated oil increased to 110.0 mPa.s. Hence, formation pore structure should be underestimated by using NMR log in heavy oil-bearing reservoirs. In addition, for core samples drilled from ultra-tight sandstones, the NMR T2 distributions exhibited as similar morphological characteristics under four saturation conditions. The reason was that oil cannot be injected into the pore spaces due to high capillary pressure and poor pore connectivity in such type of rocks. These experimental results could give us good indication that the shapes of field NMR T2 spectra should be first corrected to remove the effect of crude oil before they were used for formation pore structure characterization at a particular state of saturation.

OnePetro

SPWLA

SPWLA-JFES-2022-D

SPWLA 27th Formation Evaluation Symposium of Japan

China University, Comparison, Formation Evaluation Symposium, log analysis, Looyestijn, nmr experiment, oil-bearing reservoir, permeability, relaxation, reservoir, Sandstone Reservoir, saturation, spectra, spectrum, Symposium, University, Upstream Oil & Gas, viscosity, well logging

Country:

North America > United States (0.94)
Asia > China (0.73)
Africa > Cameroon > Gulf of Guinea (0.24)

Genre: Research Report > New Finding (0.70)

Geophysics: Geophysics (0.46)

Industry: Energy > Oil & Gas > Upstream (1.00)

Oilfield Places:

North America > United States > Louisiana > China Field (0.99)
Asia > China > Sichuan > Sichuan Basin (0.99)

SPE Disciplines: Reservoir Description and Dynamics > Formation Evaluation & Management > Open hole/cased hole log analysis (1.00)

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Research on Impact Energy and Damage of Subsea Protection Structures by Trawling Board

Huang, Zheng (College of Shipbuilding Engineering, Harbin Engineering University, Harbin) | Wang, Honghong (CNOOC Research Institute, Beijing) | Zhang, Wei (College of Shipbuilding Engineering, Harbin Engineering University, Harbin) | Chen, Rongqi (Offshore Oil Engineering CO. LTD, Tianjin) | Liu, Yanbo (College of Shipbuilding Engineering, Harbin Engineering University, Harbin)

OnePetroJune, 2022

ABSTRACT Panels with frames have been applied as protection structures of subsea production systems for reducing the damages caused by dropping objects and trawling boards. However, current standards do not provide calculation methods for the impact energy of trawling board and damages of protection structures in specific region. For investigating the impact process in specific regions, data statistics based on AIS and multivariable simulations are conducted in this paper. Simulations suggest that pile-soil interaction has a good inhibitory effect on structural vibrations and panel depressions. The simulation results also show that protective structure with FRP panel has less overall displacement but greater depression than structures with steel panels. INTRODUCTION Bottom trawling is one of the most common operation methods used by fishing vessels. During bottom trawling operations, the trawling board may impact subsea equipment, which seriously threatens the safety of the underwater production system. Therefore, protection structures have been apllied to prevent the damages from impact of trawling board. Most protection structures are fabricated with steel pipes and plates. In some protective structures, fiber reinforced polymer (FRP) is also used as the panel material. Previous researches usually adopted the extended theory and damage models of researches about impacting process of subsea pipelines to analyze the impact energy and structural damage of the protection structures. Ellinas (1995) proposed a semi-empirical formula to calculate the impact forces and the pipeline depressions, which are in good agreement with the experimental results and have widely used in the subsequent damage analysis. Bai (1993) used nonlinear spring theory to analyze the impact between trawling board and circular pipes, a mass-spring formula for calculating the impact force on subsea pipes summarized in his research for integrating the impact force along the path of the pipe depression to solve the impact energy. Based on experimental data, DNVGL (2017) improved the calculation formula of pipe deformation and impact force of trawling board. In the researches conducted by DNVGL, a calculation method based on maximum deformations theory is proposed to calculate the impact of energy and pipeline damages.

OnePetro

ISOPE

ISOPE-I-22-492

The 32nd International Ocean and Polar Engineering Conference

Country: Asia > China > Hainan (0.28)

Industry:

Transportation > Marine (1.00)
Materials > Metals & Mining > Steel (1.00)
Energy > Oil & Gas (1.00)

Oilfield Places:

Asia > China > South China Sea > Yinggehai Basin > Block DF 13-2 > Dongfang Field (0.99)
Asia > China > Hainan > Yinggehai Basin > Ledong Field (0.99)

SPE Disciplines:

Facilities Design, Construction and Operation > Offshore Facilities and Subsea Systems (1.00)
Data Science & Engineering Analytics > Information Management and Systems (1.00)
Facilities Design, Construction and Operation > Pipelines, Flowlines and Risers > Offshore pipelines (0.49)

Technology: Information Technology > Modeling & Simulation (0.34)

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Collaborating Authors

Zhang, Wei

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Intelligent Wireline Formation Tester Evaluation of Low-Permeability and Low-Resistivity-Contrast Formation

A New Experimental Core Analysis Method for Formation Permeability Measurement Under Two-Phase Condition

Characterization of Tight Sandstone Reservoir Pore Structure and Validity from Geophysical Logging Data by Using Deep Learning Method

Scaling Equations for Benchtop Laboratory Simulator of Wellbore Hydraulics

Elastic Characterization of Shale at Microscale: A Comparison between Modulus Mapping, PeakForce Quantitative Nanomechanical Mapping, and Contact Resonance Method

The Positive Effect of Geomechanics on Adsorption and Transport Processes During Co2 Huff-N-Puff in Organic Shale

Comparative Study on Predicting Ship Maneuvering in Waves Using a Quasi-Steady Method and a Time Domain Approach

Effect of Crude Viscosity to Nuclear Magnetic Resonance (NMR) Responses in Different Types of Reservoirs: An Experimental Study

Research on Impact Energy and Damage of Subsea Protection Structures by Trawling Board

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Zhang, Wei