首页期刊导航|Journal of Petroleum Science & Engineering
期刊信息/Journal information
Journal of Petroleum Science & Engineering
Elsevier Science B.V.
Journal of Petroleum Science & Engineering

Elsevier Science B.V.

0920-4105

Journal of Petroleum Science & Engineering/Journal Journal of Petroleum Science & Engineering
正式出版
收录年代

    The use of distributed acoustic sensing(DAS)in monitoring the integrity of cement-casing system

    Xiaorong LiYijin ZengNguu Dickson Muchiri
    12页
    查看更多>>摘要：The integrity of cement sheath and the interface bonds of the cement-casing-formation system is critical in the oil and gas wells'productive life and even after its abandonment.For many years,cement bond logs(CBL)tools,as one of the vital logging techniques,have been extensively employed in industry to monitor and evaluate cement-casing-formation bonds.Though these techniques provide a clear view of cement sheath integrity quality,some controversies surround their applications.First,it is challenging to deploy these logs in extremely harsh environments.Second,it is impossible to obtain real-time diagnostic values with CBL logs since they only provide a snapshot in time.Undoubtedly,real-time monitoring of cement sheath integrity is critical to operational safety in oil and gas wells.Distributed acoustic sensing(DAS)has emerged as a novel technology to provide the industry with an opportunity to improve safety during production and minimize operational costs.There are various aspects of well integrity in which DAS would provide invaluable information to support decision-making for well integrity management.In this paper,we firstly present a review of cement sheath integrity evaluation with conventional logs,then a comprehensive review of distributed acoustic sensing technology,including deployment methods,working principle,data processing/analysis techniques,and the current advancement in the use of DAS in wells'integrity monitoring.We find that specially packaged DAS sensors exhibit extreme sensitivity to events occurring downhole and thus provide a trove of valuable information.Once this data is acquired,it is processed and analyzed to highlight acoustic components related to a particular event signature enabling events classification.However,we have noted that there is still a long way to go in realizing the full potential of DAS in cement sheath integrity monitoring.Therefore,to fast-track the maturation of DAS application in oil and gas well integrity evaluation,there is a need to develop laboratory simulation tools and methods.
      原文链接:
    • NSTL

    Modeling the hydrodynamic behavior of fractures and barriers in porous media using coupling finite elements

    Murilo CamargoPedro R.CletoMichael A.Maedo
    19页
    查看更多>>摘要：Fractures,vugs and barriers are geological structures that strongly affect the fluid flow in porous media.While the first two lead to the formation of preferential flow paths,the latter blocks the flow and induces discontinuities in the pressure field.The difference in scale between these structures and the porous medium can be significant and,therefore,appropriate numerical models are required to take into account their interactions.In the context of the finite element method,this work presents a methodology to couple equi-dimensional and independent meshes(i.e.,non-matching meshes)of geological structures and the porous medium by using coupling finite elements(CFEs),which are able to connect the meshes via a penalty method that ensures the continuity of the pressure field.This technique is easy to implement and does not require any special formulation,since the shape functions of the CFE are the ones used in conventional finite elements.Moreover,the addition of the CFE does not increase the number of degrees of freedom of the problem.In order to show that the technique has great potential to capture the main phenomena related to the fluid flow problem in a porous medium,2D single-phase flow numerical experiments were conducted by considering different geological structures,geometries and boundary conditions,with incompressible fluid.The methodology was validated by comparing the results obtained with several DFM methods available in the literature as well as considering matching meshes between matrix and fracture.The results showed that the proposed coupling scheme applied to equi-dimensional meshes is adequate to reproduce the influence of geological formations such as fractures,vugs and barriers on the hydrodynamic behavior of fluids in porous media.
      原文链接:
    • NSTL

    Application of a constructive method in solving the composite reservoir model of dual-porosity media with fractal characteristics

    Wei LiShunchu LiSonglin Zhang
    16页
    查看更多>>摘要：In this paper,we apply a constructive method to solve the extended Bessel differential equations with boundary value problem(BVP).Considering wellbore storage and skin effects,a dual-porosity composite reservoir model with fractal characteristics and three typical exterior boundary conditions is established.After symbolic comparison,the reservoir model is identical to the BVP proposed above,and the solving of the reservoir model is naturally reduced to the solving of the BVP.Based on the Laplace transform and a constructive method,the Laplacian space solutions of fracture system pressure and wellbore pressure in the two zones are obtained.The type curves of wellbore pressure and the pressure derivative are plotted with the aid of the Stehfest numerical inversion technique,the flow regimes are identified,and the effects of fractal and reservoir parameters on the type curves are analyzed.Compared with the traditional method,the similar constructive method is more efficient and fast in solving complex reservoir models,which is of great value in designing and implementing well-test analysis algorithms for complex reservoirs.
      原文链接:
    • NSTL

    A real-world impact of offset frac-hits by rate transient analysis in the Bakken and Three Forks,North Dakota,USA

    Amin TaghavinejadCody BrownMehdi Ostadhassan
    24页
    查看更多>>摘要：Production via multi-fractured horizontal wells with specific spacing units is a common development plan in shale plays.Commonly,operators drill and complete a single well in order to hold a 1280-acre spacing unit and once the acreage is secured across the asset,infill wells at each spacing unit are drilled so,depletion from the original(parent)well can be observed within the spacing unit.This will increase the likelihood of existing wells to experience inter-communication when infill wells are hydraulically fractured which has detrimental effects.Hence,understanding the effects of well timing and spacing on the performance of the overall spacing unit is critical to choose an appropriate development plan.In this regard,rate transient analysis(RTA)is an effective way to quantify the impact of offset frac-hits,hinting the changes in reservoir properties such as stimulated reservoir volume(SRV)and well productivity.In this real-world study,we used pseudo normalized pressure versus material balance square root of time plots to determine the impact of offset frac-hits on existing wells in Williston Basin,ND.The slope of the superposition time plot is inversely proportional to the product of the contacted surface area(AJ and the square root of reservoir permeability(Vk),A
      原文链接:
    • NSTL

    Methodology for the prediction of fluid production in the waterflooding process based on multivariate long-short term memory neural networks

    Astrid X.RodriguezDiego A.Salazar
    12页
    查看更多>>摘要：Given the depletion of hydrocarbon reserves,the oil industry is developing enhanced recovery processes,including waterflooding,to increase the quantity of hydrocarbon to be extracted from each reservoir.However,one of the main challenges in assessing these processes is predicting water and oil production associated with the method,given the uncertainty,lack of reservoir information,and access to commercial software.This work proposes a methodology based on multivariate Long-Short Term Memory(LSTM)Neural Networks to predict oil and water production time-series in an oil field exploited through waterflooding.First,we used the oil and water production's time series of the producer wells in an inverted five-point injection pattern developed in a numerical reservoir simulation software based on a Colombian oil field exploited with waterflooding.In this scenario,we evaluated three multivariate LSTMs to determine the input features mat should be included.Thus,through a define-by-run process,we assessed the LSTM structures most suitable.Finally,we found that the information obtained by operational variables,such as bottom-hole pressure or water injection rate,allows significant approximations to predict oil or water production.
      原文链接:
    • NSTL

    Comparisons of predictive ability of THAI in situ combustion process models with pre-defined fuel against that having fuel deposited based on Arrhenius kinetics parameters

    Muhammad Rabiu Ado
    12页
    查看更多>>摘要：Toe-to-heel air injection(THAI)is an in situ thermal-enhanced oil upgrading and recovery technology that makes use of a horizontal producer well for mobilised partially upgraded oil production to the surface.To design operation of the THAI process requires up-scaling lab-scale numerical model to field-scale reservoir numerical model.There are a number of up-scaling methods that were developed.However,these previous up-scaling methods only concentrated on the qualitative nature of the physicochemical processes.Furthermore,these methods have deficiencies ranging from assumption of 100% oxygen utilisation,failing to compare oil production rates for up-scaled reservoir models with and without fuel pre-defined,not reporting on the dynamics inside the reservoirs with and without fuel pre-defined,etc.As a result,this work provided in depth comparative studies of both the qualitative and quantitative physicochemical processes in numerical models containing Arrhenius-based coke deposition thermal cracking reaction(i.e.model A)and that having pre-defined fuel concentration(i.e.model F)as an initial parameter respectively.It is found that oil production started earlier in model A compared to in model F even though they have approximately similar trajectories.It is shown that by the end of the combustion period,oil recovery of 28.5% OOIP is achieved in model F which is greater than that in model A by an additional of 4.8% OOIP.It is found that the peak temperature,which indicates how healthy the combustion is at a single point only at different times,is generally considerably higher in model A than that in model F.It is further discovered that in some cases the combustion at all points might be stable and rigorous but in other cases the combustion might not be stable and rigorous at all points thereby implying that the peak temperature alone does not give the measure of the efficiency and spread of the combustion front.It is shown for the first time that pre-defining fuel concentration throughout the reservoir as is done in model F resulted in faster downward advancement and expansion of the combustion front compared to in the reservoir where the fuel is deposited based on the Arrhenius kinetics parameters(i.e.like in model A).It is also discovered that higher areal sweep of the reservoir is achieved in model F when compared to that achieved in model A.Overall,it then follows that higher volume of the reservoir of model F is combustion-swept,heat-affected,and oil-depleted compared to that in model A.These findings explain the reason why more oil is produced during the combustion period in model F than in model A.Conclusively,this first-of-a-kind study shows that pre-defining the fuel has no effect on the qualitative nature of the physicochemical processes,but has considerable influence on the quantitative parameters such as the rate of and cumulative oil production,peak temperature,areal and volumetric sweeps by the combustion zone,size of the oil-depleted zone,and size of the heat-affect zone.
      原文链接:
    • NSTL

    A new image-based microfluidic method to test demulsifier enhancement of coalescence-rate,for water droplets in crude oil

    Yuan Si TianZi Qiang YangSigurdur T.Thoroddsen
    11页
    查看更多>>摘要：The separation of water droplets from water-in-crude-oil emulsions is a vital process in the petroleum industry.Various components in crude oil,such as asphaltene,stabilize the water-oil interface,which inhibits the coalescence of water droplets.To enhance the oil-water separation,specific demulsifiers are often added to destabilize the emulsion and enhance the coalescence of the water droplets.In this work,we propose a new method to select an effective demulsifier and optimal concentration for a water-in-crude oil emulsion.This new experimental design involves an optical-access flow in a long 500 μm-square micro-fluidic channel,illuminated by a Near-Infrared laser and imaged with a B/W high-speed video camera.We can quantify the coalescence probability by using monodisperse droplets and identifying coalescence by their change in size.Coalescence probability is an indicator for selecting the optimal concentration and type of demulsifier.
      原文链接:
    • NSTL

    An internally consistent procedure to characterize single carbon number fractions for phase equilibrium of petroleum mixtures:Application to Brazilian pre-salt reservoir fluids

    Tobias R.GessnerJader R.Barbosa Jr.
    11页
    查看更多>>摘要：Each natural accumulation of hydrocarbons has unique chemical and molecular characteristics.A complete experimental assessment of every substance involved is impossible and,in most cases,gaps left by laboratory tests must be filled by empirical correlations to provide the minimum set of parameters necessary for the proper functioning of a thermodynamic model.In the present work,a new procedure is developed for calculating the critical properties and acentric factor of single carbon number(SCN)fractions,valid for the C7-C22 interval(Mw ≤ 300g/mol)and successfully tested for mixtures containing heavy fractions with average molecular weights up to 520 g/mol.The proposed method is based on a refit of existing correlations that fully respects the internal consistency of the equations.These,in turn,were selected by observing the trends described by the critical compressibility factor in the Soave-Redlich-Kwong(SRK)and Peng-Robinson(PR)cubic equations of state,resulting from the introduction of a volume translation parameter.After applying the new procedure to characterize ten oil samples collected from High-Pressure High-Temperature(HPHT)reservoirs in the Brazilian pre-salt cluster,thermodynamic parameters derived from flash and differential liberation tests were successfully predicted.With average absolute deviations of 8.38% and 8.32% for the SRK and PR equations of state,respectively,the proposed method is superior(or at least equivalent)to other characterization schemes considered in the study,with the advantage of being thermodynamically consistent.
      原文链接:
    • NSTL

    Information content in 4D seismic data:Effect of correlated noise

    Dean S.Oliver
    10页
    查看更多>>摘要：Several types of data used in history matching for subsurface reservoir characterization have errors that are spatially or temporally correlated.Although it is often assumed that correlated observation errors decrease information content,using a simplified flow problem,we show that for data that are spatially dense(such as 4D seismic data),correlated observation errors result in higher information content than data with similar levels of errors,but without correlation.Unfortunately,correlations in the observation error are often unrecognized and difficult to estimate,especially if the correlation scale of the errors is similar to a characteristic length of the signal.In addition,many history matching algorithms are incapable of accounting properly for correlated observation error,so data are either thinned or the observation error is inflated to partially account for the lack of proper treatment.We show that neglecting correlations in the observation errors or inflating the variance,result in loss of information content.Finally,we show that it is possible to iteratively estimate the correlated observation errors through analysis of residuals after history matching.
      原文链接:
    • NSTL

    Sensitivity analysis of injection parameters in steam assisted gravity drainage under geological uncertainty

    Lua MonteiroCatarina Baptista-PereiraLeonardo Azevedo
    13页
    查看更多>>摘要：Steam-assisted gravity drainage(SAGD)is a challenging enhanced oil recovery technique that requires proper parameterization in terms of well geometry and steam injection parameters as these parameters are highly dependent on the reservoir geology and fluid characteristics(e.g.,net pay variation,water saturation).Injection rate and pressure,temperature,steam quality,lean zone,gas zone,water saturation,and wellbore hydraulics are among the most important engineering parameters of SAGD.This work focuses in the sensitivity analysis under geological uncertainty of some operational parameters,such as:injection rate,temperature,steam quality and pressure.To reach this objective we build a realistic reservoir model with multiple geological settings and descriptions.Moreover,two complementary approaches were studied:i)a deterministic sensitivity analysis relying on a factorial design matrix and ii)a stochastic analysis using particle swarm optimization.There are several key geological uncertainties in SAGD,such as net pay variation,inclined heterolithic stratification(IHS)presence,high water saturation in reservoirs,bottom water issues,and gas cap problems.This work focuses on the role of porosity and permeability in oil production,as these impact these geological properties.To reach this objective,two specific groups of ten different porosity and permeability pairs of geostatistical realizations were generated using Direct Sequence Simulation and Co-simulation.Group 1 used the same variogram model for 10 random seeds;and Group 2 used a combination of values that adopted a simultaneous and a random variation,which were assigned to the seed and to the variogram.We opted by a reservoir model that mimics an anticlinal reservoir,as it proved to be a determining factor for the low levels of Net Present Value(NPV)when compared to other geological scenarios.Within the four most commonly studied parameters in SAGD projects,the association of deterministic versus stochastic multi-objective analysis allowed to accurately validate injection rate as the I most relevant parameter.Regarding the geological uncertainties,Group 1 showed that for a certain porosity distribution and permeability orientation,the random origin of these distribution maps eventually attributed a higher NPV uncertain.On the other hand,in Group 2,the simultaneous spatial and seed variation provided less'uncertainty associated to NPV.'
      原文链接:
    • NSTL