Reservoir Location Research Articles

Deep magma storage during the 2021 La Palma eruption.

The 2021 La Palma eruption provided an unpreceded opportunity to test the relationship between earthquake hypocenters and the location of magma reservoirs. We performed density measurements on CO2-rich fluid inclusions (FIs) hosted in olivine crystals that are highly sensitive to pressure via calibrated Raman spectroscopy. This technique can revolutionize our knowledge of magma storage and transport during an ongoing eruption, given that it can produce precise magma storage depth constraints in near real time with minimal sample preparation. Our FIs have CO2 recorded densities from 0.73 to 0.98g/cm3, translating into depths of 15 to 27km, which falls within the reported deep seismic zone recording the main melt storage reservoir.

Improving off-structure carbonate reservoir characterization using integrated Shared Earth Approach and Forward Stratigraphic Modelling: The Marrat Fm of southern Kuwait

A high-resolution reservoir characterization workflow is applied to assess the off-structure prospectivity of Lower Jurassic complex carbonate reservoirs of the Marrat Formation in the southern part of The State of Kuwait along the Dharif-Abduliyah fields. A detailed sedimentological and petrophysical assessment was integrated with 3D seismic interpretation and delineated vertical and lateral facies changes within the fields, which are affected by sets of complex fault patterns. Carbonate geo-bodies have been mapped using seismic stratigraphy, and 3D multi-seismic attribute and seismic acoustic inversion workflows. The Middle Marrat has been subdivided into 5 units (Middle Marrat 1-MM1 to Middle Marrat 5-MM5) that show vertical and lateral lithological and facies variability. The developed integrated sequence stratigraphic framework permitted to better assess the influence of accommodation variations as well as carbonate ecological settings on sedimentary facies development. This framework pointed to the influence of marine incursions and subsequent flooding surfaces, on the development of wackestone to mudstone textures interbedded within porous grainier inner ramp/shoal reservoir intervals. This integrated Shared Earth Approach that combined the various multi-disciplinary and multi-scale results was supported for the first-time by high resolution Forward Stratigraphic Modelling to provide a mapping and identification of petroleum systems elements including potential reservoir locations and baffles as well as stratigraphic trapping mechanisms. This workflow opens a new perspective to increasing hydrocarbon reserves along the Dharif and Abduliyah Fields as well as many other fields along the State of Kuwait.

An Improved Unscale S-Transform in Frequency Domain

The time–frequency analysis methods are powerful tools in seismic interpretation and bright spot identification. The S-transform (ST), as a hybrid of the short-time Fourier transform (STFT) and continuous wavelet transform (CWT), can achieve progressive time–frequency resolution. However, limited by its linear-frequency-dependent term, the ST obtains a deviated frequency distribution. By removing this term, the frequency form of unscaled ST (FUST), as a variation of the ST, is proposed to preserve the reliable frequency distribution. The fly in the ointment is that the FUST decreases the temporal resolution of the low-frequency components, which may not be suitable for seismic reflection interpretation and reservoir location. In addition, the ST cannot tailor the time–frequency resolution for particular applications. To solve these problems, a simple and effective method is proposed by substituting the basis of the FUST. The proposed method can obtain the desired time resolution by adjusting two adjustable parameters. The corresponding inverse transform is also derived to guarantee its energy conservation and inevitable property. Numerical experiments and real data examples show better performance of the proposed method in improving temporal resolution and reservoir location over the ST and FUST.

Frequency-Dependent AVO Inversion Using a Modified Window-Parameter-Optimized S-Transform for High Gas-Saturation Reservoir Delineation

The dispersion induced by fluid flow is a useful characteristic of hydrocarbon reservoirs and can be deduced from frequency-dependent amplitude versus offset (FAVO) inversion. However, FAVO inversion strongly depends on the spectral decomposition method, which directly affects the resolution of inversion results. In this letter, we propose a new time-frequency analysis method, named modified window-parameter optimized S-transform (MWPOST), for improving the resolution of FAVO inversion. In MWPOST, the optimized scale parameter of the window function can be adaptively obtained according to the amplitude spectra of actual signals. Synthetic signal analysis indicates that the method has excellent performance with higher time-frequency resolution. Then, we present a high-precision FAVO inversion method using MWPOST for high gas-saturation reservoir delineation. The field seismic data application illustrates that the dispersion factor inverted by the proposed method has a higher time resolution and exhibits better performance for delineating the reservoir boundary with high gas saturation. The proposed method can improve the precision of FAVO and it is feasible to detect the location and spatial distribution of high gas-saturation reservoirs.

Flood Control of Kupang River, Pekalongan

The local community in Pekalongan suffered financial losses as a result of the Kupang River flood. To control floods in the Kupang watershed, this research aims to identify the most effective way to lower the discharge that flows downstream due to heavy rainfall. HEC-HMS modeling was used to analyze flood discharge. The result from an analysis of flood discharge in the existing conditions downstream of the Kupang River with a 100-year returns period is 641.6 m3/s. This study will include 9 locations of the potential reservoir as flood control that will be simulated using small dams and dry dams. The discharge analysis results from modeling a small dam can reduce the discharge by 261.9 m3/s, or 40.8%. On the other hand, the dry dam simulation can reduce flood discharge by 406 m3/s, or 64.8%. According to the analysis's results, using a dry dam to reduce the amount of water that is discharged into the upstream watershed is the most efficient way to manage floods. As a result, the dry dam method is ideal for controlling floods from the Kupang upstream watershed.

Seismic properties of the permafrost layer using the HVSR method in Seymour-Marambio Island, Antarctica

Authors have calculated the H/V spectral ratios using seismic-noise recordings in the uppermost layers north of the Seymour-Marambio Island, Antarctic. Sixty-seven seismic site-response measurements near and far from the Argentinean Marambio Base runway suggest geotechnical works on the uppermost sedimentary layers due to maintenance, landing, and taxi of large loads and aircraft during decades could contribute to changes in their seismic dynamic response. Two horizontal images of Vp, Vs, and Vp/ Vs ratios at 1.0 m and 35.0 m depth show lateral variations in the permafrost properties. Authors interpret that permafrost is emplaced in rocks with different porosities and contrasting fluids saturation at those depths. In shallow strata, the saturation of gases affects mainly the elastic properties. In deeper strata, where the location of water reservoirs is detected, the primary mechanism of seismic dissipation is anelastic.

A Deep Learning Method Based on Two-Stage CNN Framework for Recognition of Chinese Reservoirs with Sentinel-2 Images

The development of effective and comprehensive methods for mapping and monitoring reservoirs is essential for the utilization of water resources and flood control. Remote sensing has the great advantages of broad spatial coverage and regular revisit to meet the demand of large-scale and long-term tasks of earth observation. Although there already exist some methods for coarse-grained identification of reservoirs at region-level in remote sensing images, it remains a challenge to recognize and localize reservoirs accurately with insufficiency of object details and samples annotated. This study focuses on the fine-grained identification and location of reservoirs with a two-stage CNN framework method, which is comprised of a coarse classification between aquatic and land areas of image patches and a fine detection of reservoirs in aquatic patches with precise geographical coordinates. Moreover, a NIR RCNN detection network is proposed to make use of the multi-spectral characteristics of Sentinel-2 images. To verify the effectiveness of our proposed method, we construct a reservoir and dam dataset of 36 Sentinel-2 images which are sampled in various provinces across China and annotated at the instance level by manual work. The experimental results in the test set show that the two-stage CNN method achieves an average recall of 80.83% nationwide, and the comparison between reservoirs recognized by the proposed model and those provided by the China Institute of Water Resources and Hydropower Research verifies that the model reaches a recall of about 90%. Both the indicator evaluation and visualization of identification results have shown the applicability of the proposed method to reservoir recognition in remote sensing images. Being the first attempt to make a fine-grained identification of reservoirs at the instance level, the two-stage CNN framework, which can automatically identify and localize reservoirs in remote sensing images precisely, shows the prospect to be a useful tool for large-scale and long-term reservoir monitoring.

Dissolved oxygen concentration and eutrophication evaluation in Yamchi dam reservoir, Ardabil, Iran

One of the essential issues in the quality management of water resources is the determination of the level of eutrophication and dissolved oxygen in dam reservoirs and other water bodies. It is possible to study changes in dissolved oxygen concentration using qualitative models. In this study, CE-QUAL-W2, a two-dimensional model of hydrodynamics and water quality capable of predicting the behavior of aquatic ecosystems, has been used to simulate dissolved oxygen concentration and eutrophication. As a case study, the water quality of the Yamchi dam reservoir, located in Ardabil Province, has been qualitatively investigated using the CE-QUAL-W2 model. Based on the geographical location of the Yamchi dam reservoir, it includes warm monomictic basins. According to the results, the dissolved oxygen concentration in the simulation period varied between 0 and 12 mg/L. In autumn and winter, this concentration was almost uniform at various depths. However, in summer, a sharp decrease in dissolved oxygen concentration, to less than 2 mg/L in the bottom layers, was observed, which is due to the presence of nutrients. Regarding eutrophication, the Yamchi dam reservoir is one of the eutrophic reservoirs, and practical strategies should be employed to improve these conditions. Recommended strategies include reducing the retention time of water in the reservoir, dewatering from the underlying layers during the thermal stratification period, and preventing the entry of agricultural drains into the inlet tributaries of the reservoir.

Physics-informed machine learning with differentiable programming for heterogeneous underground reservoir pressure management

Avoiding over-pressurization in subsurface reservoirs is critical for applications like CO_2 sequestration and wastewater injection. Managing the pressures by controlling injection/extraction are challenging because of complex heterogeneity in the subsurface. The heterogeneity typically requires high-fidelity physics-based models to make predictions on CO_2 fate. Furthermore, characterizing the heterogeneity accurately is fraught with parametric uncertainty. Accounting for both, heterogeneity and uncertainty, makes this a computationally-intensive problem challenging for current reservoir simulators. To tackle this, we use differentiable programming with a full-physics model and machine learning to determine the fluid extraction rates that prevent over-pressurization at critical reservoir locations. We use DPFEHM framework, which has trustworthy physics based on the standard two-point flux finite volume discretization and is also automatically differentiable like machine learning models. Our physics-informed machine learning framework uses convolutional neural networks to learn an appropriate extraction rate based on the permeability field. We also perform a hyperparameter search to improve the model’s accuracy. Training and testing scenarios are executed to evaluate the feasibility of using physics-informed machine learning to manage reservoir pressures. We constructed and tested a sufficiently accurate simulator that is 400 000 times faster than the underlying physics-based simulator, allowing for near real-time analysis and robust uncertainty quantification.

Spatial and temporal evolution of paleo-highs/lows of the permian strata and its petroleum significance in the Sichuan basin, SW China

ABSTRACT The Sichuan basin has a great potential for hydrocarbon exploration. In recent years, Permian strata have been identified as one of the main target strata for natural gas exploration in the Sichuan basin. Not only the source rocks are abundant, but also there are good reservoirs due to the wide and complex continental oceanic interaction. However, there are still many shortcomings, especially the relationship between the tectonic evolution and the hydrocarbon accumulation model. Therefore, this research aims at understanding the characteristics of paleo-highs/lows of the Permian strata and their controlling effects on hydrocarbon migration/accumulation in the Sichuan basin. Firstly, the distribution patterns of paleo-highs/lows in the Permian strata at each critical tectonic period were constructed by integrating spatial erosion calculation. Then the temporal evolution of the Permian strata at each critical tectonic period will be revealed by restoring the upper strata sequentially. The results of this research improve the precision of paleo-highs/lows reconstruction and provide useful hints for the hydrocarbon exploration of the Sichuan basin: (i) Paleo-highs/lows directly determine the development location of the Permian key reservoirs; (ii) Tectonic evolution controls many factors and the process of hydrocarbon accumulation.

Pore systems and organic petrology of cretaceous Mowry and Niobrara source-rock reservoirs, Powder River Basin, Wyoming, USA

The Powder River Basin (PRB) is a world-class oil province, in large part thanks to contributions from premier source rocks, Cretaceous Mowry and Niobrara shales. Both formations are also unconventional reservoirs. A critical aspect of evaluating production potential and finding sweet spots is the nature of the pore systems in these fine-grained source-rock reservoirs. Variation by stratigraphic interval is important for selecting optimum target zones for horizontal wells. Understanding variation in pore type, size, and connectivity and relationships with mineralogy and fabric help in determining prospectivity in different parts of the basin. Deciphering controls on pore-system development helps predict intervals and locations of optimum reservoir quality.Imaging of Niobrara and Mowry samples from a range of thermal maturities provided observations and data on pore systems, organic matter (OM) types and associations with mineralogy and fabric, wettability, and microporosity associated with both diagenetic and detrital clays. Imaging techniques included scanning electron microscopy, organic petrography and correlative scanning electron microscopy, and mapping of mineralogy through energy dispersive spectroscopy.Mean solid bitumen (BRo) and vitrinite reflectance (VRo) values indicate all samples are in the oil window with values ranging from 0.52 to 1.15%. Organic fluorescence is prominent in amorphous OM, solid bitumen and some vitrinite in the early oil window. The fluorescence is extinguished at higher thermal maturity. Carbonate pellets (in Niobrara) mainly contain migrated solid bitumen and residual live oil and little or no terrigenous OM (vitrinite and inertinite). However, terrigenous OM is common in siliceous/argillaceous laminae in both formations, where it occurs with amorphous OM, some of which has converted in situ to a solid bitumen petroleum residue.One key finding is the widespread presence of migrated OM at very early oil window maturity. Distribution of such OM and associated wettability alteration is fabric-controlled, at all levels of thermal maturity studied. Clay morphology and abundance and supporting rigid mineral grain framework strongly influence pore development, preservation, and connectivity in both formations. Carbonate content is a good proxy for reservoir quality in Niobrara intervals due to association of porous solid bitumen with calcareous fecal pellets. High recrystallized microquartz content is associated with the best reservoir intervals in the Mowry.

GIS Modeling to Climate Change Adaptation by Reducing Evaporation in Water Reservoirs: Smart Location Technique of Minimal Evaporation Reservoirs (GIS-MER)

The ideal emplacement of reservoirs has been traditionally determined by means of GIS tools to prospect large areas applying criteria related to rainfall, substrate impermeability or economic and social viability. More recently, geomorphometric characteristics have been added to determine more suitable locations for dams and reservoirs depending on their dimensions. This study presents a fully automatized ArcGIS Pro model, suitable for working with several digital elevation model resolutions and for evaluating best potential reservoir locations to reduce evaporation losses. Here, a smart location strategy to preserve water resources is used based on the premise that the higher the ratio of water stored to water surface area of the reservoir, the lower the water evaporation. The model was tested in two dissimilar basins in the province of Cadiz (SW Spain) and the results are compared with the nearby existing reservoirs. The methodology presented in this paper allows selecting the most suitable sites where it is possible to build a reservoir with a water surface smaller than other reservoirs but also able to hold an equal or greater volume of water; this also allows reducing the area occupied by the reservoir. As an example, in the first study case presented in this paper, a new reservoir could store 30.7 m3/m2 versus the current 9 m3/m2 stored in the nearby existing reservoir. This may reduce the flooded area from 25.4 to just 6.7 km2.

High-resolution time–frequency analysis based on a synchroextracting adaptive S-transform and its application

Abstract We propose synchroextracting adaptive S-transform (SEAST) by combining the adaptivity provided by the recently introduced ‘Sparse Adaptive S-transform’ (SAST) with the high resolution of synchroextracting spectral decomposition method. Traditional synchroextracting transforms are based on short-time Fourier transforms (STFTs) and their application is limited by having a fixed analysis window size for high and low frequencies and no multi-resolution features. The arbitrary window functions used in the SAST vary with frequency and amplitude, making it more suitable for non-stationary seismic signal analysis. The SEAST retains the multi-resolution advantages of adaptive S-transforms, while providing the strong time–frequency focus associated with synchroextracting transforms. The method was used to calculate seismic dispersion attributes and the resulting field data indicates that its time–frequency resolution and joint P-wave dispersion attributes can help to fine-tune identification of the location of oil and gas reservoirs.

Wetting Patterns in a Subsurface Irrigation System Using Reservoirs of Different Permeabilities: Experimental and HYDRUS-2D/3D Modeling

Precipitation in arid lands is low and often highly variable; therefore, efficient irrigation is the best approach for managing limited water supplies and irregular precipitation events for establishing seedlings. The HYDRUS-2D/3D software is a useful tool for simulating water content distribution in the design of subsurface irrigation systems, determining the proper locations of reservoir and plant, irrigation scheduling and maximizing water use efficiency. In this study, wetting patterns around the reservoirs with different permeabilities (low, medium, and high) were assessed in the field and simulated using the HYDRUS-2D/3D software. Different amounts of animal manure and wheat straw were mixed with clay fractions to produce the reservoirs with different permeabilities. The results showed that the highest soil water content was observed near the reservoir, and it decreased with distancing from the reservoir. In the high permeability treatment (with saturated hydraulic conductivity, Ks = 0.2 cm/day), a large volume of water was released for almost three days, so that more water was deep-percolated and lowered the soil water available to plant roots. In the low and medium permeability treatments (Ks = 0.08, and 0.06 cm/day, respectively), the water slowly leaked, and the maximum soil water content was observed in the 20–40 cm layer over time. The HYDRUS-2D/3D software was able to simulate water flow and soil water content during the growth period of plants, with a high correspondence between measured and simulated soil water contents (R2 = 0.90–0.95), which was higher in the lower discharges.

Seismic Anisotropic Fluid Identification in Fractured Carbonate Reservoirs

Seismic fluid identification plays an important role in reservoir exploration and development. Natural vertical fractures are common in carbonate rocks, it is essential to consider fracture-induced anisotropy in the fluid identification of fractured carbonate reservoirs. We have developed a novel Bayesian elastic impedance variation with an angle and azimuth (EIVAZ) inversion approach for directly estimating the fracture fluid indicator (FFI), which can avoid cumulative errors produced in the indirect calculation process. Under the assumption of weak anisotropy and a small incident angle, we first derive a new approximate PP-wave coefficient for horizontal transverse isotropic (HTI) media. Analysis shows that the new approximation has reasonable accuracy at angles of incidence less than 30°. To estimate the FFI from observed azimuthal P-wave seismic reflection data, we further deduce the azimuthal EI equation and establish a two-step inversion workflow. Finally, the proposed approach is demonstrated by tests on a synthetic data example and a field data set of a fractured carbonate reservoir in the Sichuan Basin (China). Results show that the model parameters can be reasonably estimated even with moderate noise levels. The estimated FFI and quasi-normal fracture weakness show relatively high values at the location of reservoirs, which reliably indicate a fractured gas-bearing reservoir.

Deep carbonate reservoir and gas prediction based on multicomponent seismic amplitude attributes — A case study

Multicomponent seismic exploration provides more valuable information for the prediction of underground structures, lithology, fluids, and fractures. Most studies on lithology estimation and fluid description using PP- and PS-wave seismic data mainly focus on relatively shallow targets with high porosity. Focusing on deep carbonate (dolomite) reservoirs with low porosity (generally less than 5%), we first analyze the characteristics of the seismic response difference between PP and PS waves, and then we combine logging data and seismic forward modeling to implement the identification of fluids using the amplitude difference between PP and PS waves. Data sets are acquired over grain beach dolomite reservoirs in the Cambrian Longwangmiao Formation, the central Sichuan Basin, Western China. The reservoirs are filled with different types of fluids (e.g., gas, water, bitumen, etc.). Based on comparisons between seismic responses of PP and PS waves, we observe that, at the location of the gas-bearing layer, PP-wave amplitude exhibits strong peaks and PS-wave amplitude finds relatively weak peaks, which is different from that obtained for the water-saturated layer. However, at the location of bitumen-filled reservoirs, PP- and PS-wave amplitudes exhibit strong peaks, and the reflection amplitude of PP waves is stronger than that of PS waves. Therefore, the amplitude difference of PP and PS waves provides valuable information and feasibility for fluid identification. We verify that the maximum peak amplitude attribute of PS waves may better characterize the distribution of porous dolomite reservoirs than that of PP waves, and using the attribute of maximum peak amplitude difference between PP and PS waves, we may distinguish gas-bearing and water-saturated layers. Comparing with actual drilling results, we conclude that our PP/PS interpretation technique is feasible for fluid identification in deep carbonate reservoirs.

Study on the development options of tight sandstone oil reservoirs and their influencing factors

The research area of tight sandstone oil reservoirs was selected, a numerical model of the oil reservoir was developed, and a study of the development options and influencing factors was carried out to analyze the influence of different development methods, physical and engineering parameters on the development dynamics. Study shows that the two main factors limiting the efficient development of tight sandstone reservoirs are reservoir properties and formation energy. Fractured horizontal well injection huff and puff development can effectively improve reservoir physical properties and timely replenish formation energy, which is suitable for the development of such oil reservoirs. In dense sandstone reservoirs, its impact on production capacity is also relatively small when the permeability ratio is small. Due to both gravity and reservoir physical properties, the permeability ratio increases, the cumulative oil production of positive rhythm reservoirs decreases and that of reverse rhythm reservoirs increases, and the location of high-quality reservoirs in the upper part of producing wells is conducive to increasing the final recovery rate. A lower oil to water viscosity ratio can significantly increase the swept volume and improve development effect. Hydrophilic reservoirs can reduce the injection pressure and increase the spread range, effectively improving the problem of inability to inject, and improving reservoir hydrophilicity through surface activators can increase reservoir recovery. The water injection rate determines the recovery rate of formation energy. Generally, the faster the rate, the higher the cumulative oil production. Therefore, the rate of water injection should be increased as much as possible, taking into account construction conditions and economic evaluation. Additionally, the effect of water injection on the development effect is different at different stages, so the appropriate timing of water injection is very important to the water injection huff and puff development effect, and the use of early water injection in this research area is not conducive. Soaking can promote pressure and fluid redistribution and improve water injection huff and puff development effect, but soaking for a long time can lead to reservoir contamination and reduce crude oil production, so the preferred time for a soaking is about 20 days.

Microearthquake location and uncertainty analysis using a Kirchhoff wavefront imaging method: A comparison with traveltime inversion and full wavefield imaging methods

The uncertainty and resolution of microearthquake location are an important topic for reservoir characterization and early warning of induced earthquakes. Many independent studies have either improved certain source location methods or applied a certain method to a data set without perhaps studying the full limitations compared with other methods. We have developed a P- and PS-wavefront imaging (WI) method to estimate the source origin time sequentially, which overcomes the unknown variable of source origin time in Kirchhoff-type imaging and helps to reduce the location uncertainties originating from the source origin time. We develop a 3D synthetic example by finite-difference modeling the realistic elastic 3C data using the SEG advanced modeling (SEAM) 4D earth model, and jointly compare the reservoir and basement microearthquake source location uncertainties based on traveltime inversion (TI), WI, and full wavefield imaging (FWIMG) methods. For each method, we also investigate the source location uncertainties between the P- and PS-wave results. Our results indicate that, using P waves and typical surface receiver arrays, TI has larger depth location uncertainties and cannot separately resolve the reservoir and basement events, whereas WI has larger horizontal uncertainties; FWIMG has the smallest horizontal location uncertainty, its depth uncertainty is similar to the WI method, and it is much smaller than the TI. Using PS waves can significantly reduce the location uncertainty compared with using only P waves for the three methods, and the full wavefield method has the smallest location uncertainty. The WI method has a moderate computation cost between TI and full wavefield methods. Data noise and velocity scaling errors change the source location uncertainties based on different imaging methods.

Two-stage semi-supervised learning inversion for reservoir physical parameters

Reservoir physical parameters are crucial indexes for reservoir description. Deep learning is a data-driven algorithm, which may avoid some issues in conventional deterministic and stochastic inversion methods, such as cumulative and approximate errors. We develop a two-stage semi-supervised learning inversion method to predict porosity, shale content, and water saturation. Firstly, an inversion network is designed to predict physical parameters from pre-stack seismic data and initial models. The Spatio-temporal characteristics of seismic data and the low-frequency structural information of the initial model can be utilized efficiently by the network. In addition, considering the high production cost of label data in exploration geophysics, we construct a semi-supervised learning inversion workflow to relieve the dependence on the label in training. The rock physics model and seismic convolution forward model are invoked as a forward process in the workflow. Finally, we propose a two-stage inversion strategy to deal with the inversion of physical parameters with different data characteristics. The proposed method is applied to a field survey successfully. A high-resolution and high-accuracy inversion result can be obtained with our method, and potential locations of the gas reservoir can be indicated by prediction results. Meanwhile, the comparisons of the two stages demonstrate that illusions in predicted water saturation can be eliminated effectively.

Determination of PCE Based on Motorcycle Behavior at Signalized Intersections in Denpasar, Bali

A very high proportion of motorcycles affect the saturated flow and motorcycle behavior in synergy stores in developing countries such as Indonesia. The Indonesian Highway Capacity Manual (IHCM) and previous research have not adopted motorcycle behavior to determine the efficiency of passenger cars in synergy. This study aims to assess PCE based on the behavior of motorcycles in synergy with and without Exclusive Stopping Space for Motorcycles (ESSM). The synergy reservoir's location was a junction with a high motorcycle volume, low side obstacles, and traffic characteristics at an approach width of 3 meters, 5 meters, and 7 meters in Denpasar City. The survey method divides the lane virtually, the size of a motorcycle to determine the headway in the field. At the same time, the saturated flow was analyzed using the discharge headway method of both normal distributed data and log normal. Linear regression analysis was used to determine PCE based on motorcycle behavior on synergy junctions both with ESSM and without ESSM. Based on motorcycle behavior, the highest PCE value is obtained beside flow behavior (0.1-1.2) and the lowest in front behavior of the stop line (0.06-0.8). In determining PCE, it is recommended to adopt the motorcycle's behavior.