Day 3 Thu, November 29, 2018最新文献

{"title":"On Subcool Control in the SAGD Producers. Part II: Localized Hot Spots Effects and Optimization of Flow-Control-Devices","authors":"M. Irani","doi":"10.2118/193369-MS","DOIUrl":"https://doi.org/10.2118/193369-MS","url":null,"abstract":"\u0000 Part 1 of this study (SPE-187956-PA) presented a method to calculate the liquid pool level from temperature profile in observation wells, provided new insight into how factors like wellbore drawdown can compromise subcool control and cause steam breakthrough, and illustrated how liquid pool depletion may result in uncontrolled steam coning with time. In Part 1, the algebraic equation for liquid pool depletion based on wellbore drawdown, subcool and emulsion productivity was generated. However, not included in Part 1 was an examination of the effect of localized hot spots on well control, which is the focus of this paper.\u0000 As a part of this study, the effect of localized hot spots is mathematically included as a virtual skin factor representing the hot spot length in the algebraic equation for liquid pool depletion. The results of this work suggest that longer hot-spot will yield to lower differential pressure and make it harder to control the steam breakthrough by choking the well at a given rate. Two important finding of this work are that: (1) the zero-differential pressure (or steam coning) in reservoirs with higher permeabilities occurs in shorter hot-spots; and (2) it is harder to control the steam coning in high permeability reservoirs after hot-spots develop.\u0000 Flow control devices (FCDs) have been extensively used in horizontal wells for conventional oil and gas production in order to prevent early water break-through or gas coning. The benefits associated with this technology in SAGD industry have been studied with reservoir simulations and validated with field experience. The cost comparisons of bridge plug at the toe and scab-liners in heel with FCD installation along the producer is typically not large, which makes the FCDs the more attractive full life cycle option in producers experiencing hot-spots. Although installation of FCDs to prevent steam coning after steam breakthrough and hot-spots creation is part of the common practice as retrofits by SAGD operators, in recent years FCDs are now often installed to improve SAGD well pair performance as part of the initial completion. Although FCDs have demonstrated potential for improving recovery in SAGD production wells, vendors use a variety of approaches when designing their FCDs independent of the liquid pool element resulting in many cases where the field results showed no improvement. It is necessary to accurately characterize different FCDs under different reservoir conditions. In this study, the liner deployed FCD and liquid pool systems are coupled, and two criteria are suggested as for a design of liner deployed FCDs on the basis of pressure drop ratio of FCD relative to the liquid pool (ΔPFCD / ΔPpool) and the coefficient of variation (CoV) of inflow for the liner deployed FCD wellbore (CoVFCD).","PeriodicalId":225138,"journal":{"name":"Day 3 Thu, November 29, 2018","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126353107","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimization of Placement of Flow Control Devices under Geological Uncertainty in Steam Assisted Gravity Drainage","authors":"S. Nejadi, S. Hubbard, R. Shor, I. Gates, Jingyi Wang","doi":"10.2118/193364-MS","DOIUrl":"https://doi.org/10.2118/193364-MS","url":null,"abstract":"\u0000 Steam chamber conformance in Steam Assisted Gravity Drainage (SAGD) influences the efficiency and economic performance of bitumen recovery. Conventional SAGD well completion designs provide limited control points in long horizontal well pairs leading to development of a non-ideal steam chambers. Developing advanced wellbore completions and optimizing downhole tool settings is critical to achieve optimal steam distribution in heterogeneous reservoirs for optimal recovery.\u0000 This paper presents a workflow to optimize SAGD well completion design by using flow control devices (FCDs). Optimum FCD placement, and specifications are determined in consideration of reservoir heterogeneity. Uncertainties in spatial distribution of facies and rock types, reservoir rock and fluid properties are represented by multiple equiprobable deterministic and stochastic geological realizations using Monte-Carlo simulation. The methodology is based on constrained nonlinear optimizationtomaximize the net present value (NPV) as the objective function. A coupled wellbore/reservoir simulation model of a well pad is implemented in the study, and the efficacy of different scenarios with varied well designs are assessed from evaluating bitumen production, steam injection, and well completion expenses.\u0000 Results indicate superior performance of the wells equipped with FCDs compared to conventional concentric and parallel dual string well completion designs. For the cases examined, this translates to an average 7% increase of the expected NPV for different well completion designs when using FCDs. Furthermore, results show using zonal isolation in the well design is essential for compartmentalized reservoirs such aspoint bar deposits with their significant heterogeneity.\u0000 Advanced wellbore completions provide sufficient tools to constrain steam injection and liquid production into and from different well segments, and manage steam chamber conformance along the horizontal well pairs, improve production efficiency, increase bitumen recovery, and reduce operating costs.\u0000 A novel workflow is presented to optimize advanced wellbore completions utilizing flow control devices. This integrated assisted optimization approach considers uncertainties in geological properties, and determines the optimal FCD parameters and well completion design with acceptable computational effort. This integrated workflow allowed us to undertake a thorough evaluation of the key subsurface uncertainties, and design an overall development plan. The probabilistic nature of the results legitimize quantifying the uncertainties and identify associated risks for different completion strategies.","PeriodicalId":225138,"journal":{"name":"Day 3 Thu, November 29, 2018","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117237466","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Addressing Thermal Loading Uncertainties for Liner Design","authors":"M. Chartier, S. M. Miller, T. Kaiser","doi":"10.2118/193356-MS","DOIUrl":"https://doi.org/10.2118/193356-MS","url":null,"abstract":"\u0000 Liners in the unconsolidated sand reservoirs common to SAGD applications are subjected to a unique combination of loads that arise due to re-established formation stresses combined with large temperature changes. Temperature changes that occur following frictional constraint of the liner induce axial strain that can yield the liner, which reduces its capacity to resist ovalisation under non-uniform re-established formation stresses. These types of liner deformations are undesirable because they can restrict wellbore access, compromise other liner functions (e.g., sand or inflow control) or, in the worst case, drive a complete collapse failure.\u0000 The magnitude, non-uniformity, and evolution of re-established formation stresses present in SAGD wells remains highly uncertain. Consequently, many of the liner designs deployed in early wells relied on approximations of the re-established formation stresses, for example, from experimental testing and analytical approximations provided by van den Hoek et. al. (2000b).\u0000 Industry experience with liners deployed in thermal applications has been mixed. Some projects have indicated very low rates of liner failures. Conversely, other projects in the same formations, or in formations with similar characteristics, have experienced higher failure rates with measured liner ovalisations that suggest re-established formation stress (REFS) distributions can be more severe than previously assumed.\u0000 This paper describes how REFS impacts long-term integrity of thermal liners in unconsolidated sand reservoirs and how uncertainty in those stresses can be the difference between success and failure. The sensitivity of thermal liner structural performance of several common liner systems to re-established formation stresses is examined. The results align with field experience and highlight the importance of developing a strong understanding of the downhole loading environment to ensure liner designs promote long-term integrity and sustained production. The paper recommends several activities that will enable industry to more rigorously determine re-established formation stress and proposes refinements to the design and selection basis for liners deployed in thermal wells to manage the risk of deformations that result from thermal loading.","PeriodicalId":225138,"journal":{"name":"Day 3 Thu, November 29, 2018","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126148220","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Visualization of Fines Migration in the Flow Entering Apertures through the Near-Wellbore Porous Media","authors":"S. Ansari, Yishak Yusuf, Lisa K. Kinsale, R. Sabbagh, D. Nobes","doi":"10.2118/193358-MS","DOIUrl":"https://doi.org/10.2118/193358-MS","url":null,"abstract":"\u0000 Various slotted liners geometries are used to control the sand production in SAGD operations. The geometry of a slot (shape and size) not only affect sand production but it may also influence fine deposition and scaling at the slot entrance. Failure of SAGD wells due to the deposition of particles is an important issue that needs to be investigated at the pore scale. This study provides a fundamental understanding of fines transport and the plugging potential at the entrance of the slots on slotted liners. Three slot profiles including straight shape, keystone shape and seamed (rolled top) shape are examined experimentally in relation to the preceding conditions of pore spaces in porous media. The potential of slot plugging is also studied from the fluid flow motion perspective. This task is achieved by visualization of the flow passing through the near well bore region of different slot geometries using an optical technique, namely, particle image velocimetry. Motion of small particles (D = 20μm) in the oil flow are captured before entering the slot, at the entrance and after leaving the slot entrance. The changes in the streamlines and velocities are analyzed to estimate the potential plugging locations. The results highlights how changing the entrance geometry of the slots may increase the deposition potential in and around a slot. The flow of the oil within the near wellbore porous media have also indicated that depending on the locations of the porous media within the flow structure, different deposition pattern may take place. Based on the result of this study it can be concluded that among the slots, keystone has the highest potential for the particle build up within and at the entrance of the slot.","PeriodicalId":225138,"journal":{"name":"Day 3 Thu, November 29, 2018","volume":"61 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131083633","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An Experimental Investigation into the Sand Control and Flow Performance of the Remedial Tubing Deployed Scab Liners in Thermal Production","authors":"Vahidoddin Fattahpour, Mahdi Mahmoudi, Morteza Roostaei, P. Nolan, Colby Sutton, B. Fermaniuk","doi":"10.2118/193366-MS","DOIUrl":"https://doi.org/10.2118/193366-MS","url":null,"abstract":"\u0000 With the aging of the SAGD projects and growing number of wells with hot-spot and sand production problems, there is a growing interest in the remedial completion with Inflow Control Device (ICD) and tubing deployed scab liner. The current study aims at better understanding the annular flow, sand transport in the annular space and the expected pressure drops and the produced sand for tubing deployed scab liner sand control solution using a large-scale experimental well simulator.\u0000 A large-scale wellbore simulator was developed to study the performance of the tubing deployed scab liner screen as remedial sand control, where the sand entry point, the concentration and PSD of the sand in addition to the flow rate and the ratio of different phases could be controlled precisely. Two-phase flow of oil and brine along with sand could be injected through different ports along the clear pipe, emulating the slurry flow entering into the wellbore. Clear pipe allows visualization of the sand transport and sand accumulation above the tubing deployed scab liner during the fluid injection. An experimental study of the performance of Wire Wrap Screen (WWS) with different aperture sizes is presented in this paper.\u0000 Results indicated the requirement of a different approach for designing the correct aperture size for remedial scab liners since using the current design sand control criteria leads to large amount of solid production. It seems that the design of aperture size for scab liners should be more toward the lower bound in comparison with the common screen designs in thermal applications. The sand entry point distance from the tubing deployed scab liner screen position was found to be the critical parameter in the sanding and flow performance of the remedial sand control. Fluid flow in the annulus causes the segregation of sand grains; finer grains are carried with fluid, while coarser grains settle closer to the injection ports. The slurry flow regime in the annulus results in continuous sand production until a stable bridge and later a stable sand bed is formed on top of the tubing deployed scab liner screen. Moreover, results showed that the main pressure drop happens across the nozzles on the tubing, while the pressure drop across the accumulated sand pack in the annulus and coupon was less significant.\u0000 This paper introduces an experimental tool for evaluating the tubing deployed scab liner performance as remedial sand control in thermal applications. The developed experimental testing and facility could help to better design and evaluate the remedial tubing deployed scab liner sand control solutions.","PeriodicalId":225138,"journal":{"name":"Day 3 Thu, November 29, 2018","volume":"191 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122485062","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Staged Risk-Based Approach for Assessing Erosion Resistance of SAGD Flow Control Devices","authors":"S. Prasad, T. Zahacy","doi":"10.2118/193349-ms","DOIUrl":"https://doi.org/10.2118/193349-ms","url":null,"abstract":"\u0000 SAGD operators are actively installing Inflow Control Devices (ICDs) in their SAGD production wells to enable production at low or ‘negative’ subcool values in order to maximize drawdown, increase fluid production rates and optimize SAGD economics. Operating the wells under higher vapour conditions could expose the ICDs to high velocity steam carrying sand particles, causing erosion and liner failure. A staged approach has been developed for assessing the relative erosion risk of candidate ICDs, including a stage one qualitative assessment, followed by analytical erosion calculations and Computational Fluid Dynamics (CFD) modeling.\u0000 In the first stage qualitative assessment, factors such as the anticipated fluid flow path, relative fluid velocity, and ICD housing design are used as inputs to estimate relative erosion rates, identify ICD surfaces where erosion rates are anticipated to be high and to rank ICD candidates based on relative erosion risk. The evaluation of potential erosion risk included consideration of both the predicted erosion severity and the probable consequences of erosive wear, which could include loss of the desired flow control response or damage to the integrity of the body or housing of the ICD. The result of the first stage is a short-list of the top-ranked ICD design candidates.\u0000 In the second stage, analytical erosion models are then used to quantify erosion rates on identified target surfaces. Flow velocities and impact angles identified in the first stage are used with analytical flow relationships, such as equations for expansion jets downstream of the flow control elements, as inputs to selected erosion models. The result of this second stage is an updated short list of top-ranked ICD designs.\u0000 Finally, coupled solid particle and fluid multiphase CFD simulations are conducted on a small set of ICD design candidates to obtain detailed results on the location and severity of erosion within the flow control element and on all the surfaces of the designs. The results of this stage are specific identification of susceptible erosion surfaces and rates, providing information for the selection of the appropriate ICD design.\u0000 At each stage, the number of ICD candidate designs under consideration is reduced. In this manner, simpler methods of analysis (qualitative assessment) may be readily applied to a large number of devices, while more intensive modeling approaches (multiphase CFD) are reserved for a smaller set of design candidates. This approach provides insights into erosion risk based on successively more in-depth analysis methods, including particle paths and erosion locations in the CFD analysis stage which may not be identified using higher-level analytical methods. These results of the CFD analysis could then be used to help improve accuracy when applying analytical erosion models.","PeriodicalId":225138,"journal":{"name":"Day 3 Thu, November 29, 2018","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127149964","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Standalone Sand Control Failure: The Role of Wellbore and Near Wellbore Hydro-Thermo-Chemical Phenomenon on the Plugging and the Flow Performance Impairments of the Standalone Sand Screen","authors":"Mahdi Mahmoudi, Morteza Roostaei, Vahidoddin Fattahpour, Alberto Uzcatequi, J. Cyre, Colby Sutton, B. Fermaniuk","doi":"10.2118/193355-MS","DOIUrl":"https://doi.org/10.2118/193355-MS","url":null,"abstract":"\u0000 Although several workflows have been developed over the years for the design of the optimal sand control solutions in thermal applications, numerous sand control failures still occur every year. This paper aims at assessing the failure mechanism of different sand control techniques and the factors contributing to the failure by analyzing different failed sand control screen samples recovered from thermal and non-thermal wells.\u0000 Several failed standalone screens have been studied, which were collected from various fields and operational conditions. The screens were first inspected visually, and then certain sections of screens/pipes were selected for more detailed study on the failure mechanism. The liners/screens were cut into sections to be studied through SEM-EDX, reflective light microscopy, X-ray micro CT scan and petrographic thin sections to better understand the localized plugging mechanism. Through the studies of several polished sections, a statistical variation of the plugging zone was found. Moreover, we further focused on the critical zones such as the inlet and outlet of the aperture and the zone adjacent to the formation to better investigate the plugging mechanism.\u0000 The study on wire wrap screen samples revealed significant plugging of the annular space between the base pipe and the screen. Extensive clay/fines buildup in the annular space led to full to partial clogging in some sections. The base pipe corrosion study reveals that the corrosion mechanism is highly flow dependent since the perforation on the base pipe was enlarged to an oval shape from the original circular shape with its larger axis pointing toward the flow direction. The size of the plugged zone was significantly higher in the outer diameter section where a mixture of the clay and corrosion byproducts plugged the near screen pore space and the screen aperture. Examined premium mesh screen samples showed that the plugging mechanism is highly sensitive to the mesh size and assembly process. The highest pore impairments were associated with mesh screens in which the mesh was directly wrapped around the base pipe causing a reduced annular gap for the flow toward the perforations. The investigation of slotted liner samples showed widest plugging zone in the slot entrance and the lowest on the slot wall. A distinct interplay of the clay and corrosion byproduct led to the adsorption of clay, forming a compacted layer over the slot wall.\u0000 This paper reviews the plugging mechanism of the standalone sand control screen obtained from the field to provide first-hand evidence of the plugging mechanism and provides explanations for some of the poor field performances. The results could help engineers to better understand the micro-scale mechanisms leading to sand control plugging.","PeriodicalId":225138,"journal":{"name":"Day 3 Thu, November 29, 2018","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131971806","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reducing Operational Cost and Accelerating Oil in a Thermal Field with Cyclic Steam Stimulation Operation in South Oman","authors":"Khalfan Mahrazy, A. Alwazeer, Khalid Salhi","doi":"10.2118/193372-MS","DOIUrl":"https://doi.org/10.2118/193372-MS","url":null,"abstract":"\u0000 Thermal recovery is becoming a main stream enhanced recovery method for heavy oil with unique challenges. The extreme nature of thermal recovery requires flexible and creative approach to address the unique challenges. One of the accepted recovery thermal methods is Cyclic Steam Stimulation (CSS). The thermal cycle starts with injection phase followed by soaking, and finally, production phase. Conversion from injection phase to production phase is considered a significant operational risk in addition to typical risks associated with oil production operations. The additional risk during the conversion to production from an injection cycle is due to the significant energy placement in the reservoir during steaming. If not controlled, high energy hydrocarbon fluids flowing back to surface can lead to loss of containment and harm to life or the environment.\u0000 Beam Pumps have been used predominantly in conjunction with insert down-hole pump and sucker rods. During injection phase, the well is operated as an injector without pumps or rods, and when the time comes to convert to a producer, rods and insert pumps are reinstalled. This conversion step from injector to producer is highest risk in the CSS well operation cycle.\u0000 After the injection cycle is completed, a significant energy is placed into the reservoir, the well is shut in for soaking period which is 1-3 days. Free flow is required after the shut in period to depressurize the well. Depressurization period extends in some cases to many weeks and would require killing the well where it's common that a well would not die off just by depressurization alone resulting in significant wait time. The amount of flow back and energy stored in the well is directly proportional to steam injection pressure and duration.\u0000 In many cases where well still retain some energy and pressure is still high for intervention, due to free flowing not subsiding, killing the well is utilized. Well killing procedures pose another set of challenges such as; pump start up challenges due to viscosity reduction, cost for brine mix and wrong pressure estimation leading to prolong interventions.\u0000 The challenges in CSS opened an opportunity for innovation where thermal wells could be attended for conversion with minimum rods taken out or rods added back in under high temperature and pressure. The new concept is a combination of dual rod Blow Out Preventer (BOP) and stripper seals set in series. A trial in November 2017 was conducted with positive results where the advantages of this innovation were clearly demonstrated. This paper is a summary of the design approach and the successful trial proving the concept.","PeriodicalId":225138,"journal":{"name":"Day 3 Thu, November 29, 2018","volume":"483 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122820007","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}