Day 3 Thu, October 31, 2019最新文献

{"title":"Performance Evaluation of Wireline-Retrievable Downhole Chemical Injection System Used in HPHT Wells","authors":"P. He, Lei Zhao, O. Bello","doi":"10.4043/29958-ms","DOIUrl":"https://doi.org/10.4043/29958-ms","url":null,"abstract":"\u0000 Downhole chemical injection (DHCI) systems provide precise wellbore production chemical management by pumping down chemicals via dedicated injection lines. Worldwide installation of DHCI systems has steadily increased as a large proportion of high-pressure, high-temperature (HPHT) wells are continuously drilled and completed in deepwater and ultra-deepwater fields. Ultra-low variable rate application in HPHT wells can help to control deposition of scales and enhance injection efficiency, which can lead to improved environmental protection, lower operating costs, high equipment reliability, and improved topside space usage.\u0000 One of the most common failures in DHCI systems is the breakdown of check valves. This issue is significant. Stringent requirements exist for a continuous injection rate above a certain cracking pressure, preventing flow from the injection line to the wellbore at shut-in conditions and creating a zero-leak seal that prevents reverse flow from the wellbore to the injection line. To meet these requirements, a so-called \"check valve\" design is generally used, in which a pressure differential valve is put in series with a check valve. The pressure differential valve sets the cracking pressure and shut-in pressure of the system while the check valve prevents reverse flow from the wellbore.\u0000 This paper is part of a series effort for developing chemical injection solutions for HPHT wells. Previous work summarizes development and qualification of a pressure differential valve at higher flow rates, while this paper presents qualification tests conducted to assess the performance of the pressure differential valve and check valve as a system for HPHT applications under extreme low flow rates. The qualification tests include initial material selection based on a sophisticated gas test, a liquid flow endurance test and a post inspection, followed by a second-round test. Test results indicate that a bubble-tight check valve can be qualified to 0.0016 gpm to 0.047gpm with a pressure rating greater than 10,000 psi and 350° F. The pressure differential valve and check valve can be used in different applications other than DHCI systems.","PeriodicalId":10927,"journal":{"name":"Day 3 Thu, October 31, 2019","volume":"24 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90331887","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":"FPSO Hull Brackets Repair by Cold Bonded Reinforcements - Project Lessons Learnt from a World First Offshore West Africa","authors":"C. Paillusseau, Xabier Errotabehere, Vito Florio, M. Bulboaca, G. Pinto, Andrea Galter","doi":"10.4043/29792-ms","DOIUrl":"https://doi.org/10.4043/29792-ms","url":null,"abstract":"\u0000 An increasing number of Brazilian floating platform units are currently entering a mature age inducing numerous asset integrity issues. As corrosion damages FPSOs’ hull structures, costly structural maintenance operations in extreme marine conditions are sometimes necessary. Crop and renew are very labor-intensive operations and usually require dry docking vessels. The nature of an FPSO operation practically demands it stays offshore, which raises several operational, safety and financial challenges. Indeed, dealing with flammable substances means that the use of conventional hot works techniques, such as welding or grinding, involves many critical safety assessments and/or production shutdowns. Thus, the challenge would be to carry out these repairs offshore while guaranteeing high safety standards and avoiding production shutdowns. FPSO operators, like SBM Offshore, have therefore been looking for a while for \"cold work\" in-situ solutions that guarantee safe and economical hull repair.\u0000 This paper will describe how SBM Offshore streamlined a world first implementation of a disruptive innovation (from TRL 5 to TRL 7 as per API) within less than a year through a partnership with COLD PAD, an industrial start-up of only 3 people at the time it was first proposed. It covers risk assessments, expert analysis, and overall qualification process.\u0000 It will also detail how Classification society was involved as well as typical lessons learnt from the project execution with a focus on the offshore campaign which took less than two weeks. Finally, the paper will provide indications on the advantages such a solution generates for FPSO hull asset integrity in terms of safety, planning, economics (reduced total cost of ownership) and how it can be extrapolated to lower OPEX for deepwater ageing FPSOs.\u0000 The business case considers an FPSO located in deepwater West Africa where, in 2016, SBM Offshore identified a set of corroded brackets in a void tank located close to two crude oil tanks. Classification Society imposed steel renewal for 4 of these brackets. After engineering assessment, it was concluded that conventional hot works would yield to a highly detrimental production disruption. At the same time, COLD PAD was finalizing the co-development with TOTAL and IFP Energies Nouvelles of an innovative alternative to \"crop and renew\" for structural reinforcement. ColdShield™ is specifically dedicated for the on-site maintenance of FPSO hulls without the need for hot works, thus avoiding production disruption for several scenarios. This original repair technique obtained a class approval with an anticipated service life of more than 10 years based on an established methodology of bonded composite reinforcement, used in other industries such as aerospace.","PeriodicalId":10927,"journal":{"name":"Day 3 Thu, October 31, 2019","volume":"21 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86329094","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":"Life Extension of Offshore Structure Using Machine Learning","authors":"S. Bhowmik","doi":"10.4043/29759-ms","DOIUrl":"https://doi.org/10.4043/29759-ms","url":null,"abstract":"\u0000 The objective of the paper is to demonstrate the Machine Learning (ML) based Structural Integrity Management (SIM) Methodology and its application for the life extension of the offshore structure. This paper also illustrates how the sensor data are used to generate an ML based predictive model and how it will be used to minimise the inspection cost without using the traditional Risk Based Inspection(RBI) methodology. Structural assessment, real-time monitoring and predictive maintenance are the three main aspects of the life extension process for the offshore structure. Usually, the structures are designed for a fixed design life, but during life extension process it is assessed through FE analysis and various inspection methods whether the structure will have adequate fatigue life for another 5-10 year. But running fatigue analysis is computationally expensive as well as inspection also increase the operational cost. Sensors are installed on the offshore structure, and the stress, acceleration, wave, current etc. are measured and transmitted through wired or wireless sensor network and stored in cloud computing. This data is used for predicting the new wave and current data for 1 and 10-year return period. The acceleration data is used to get the modal frequencies and calibrate the FE model. Also, the measured stress value is compared with the FE model generated stress value, and the FE model is further calibrated.\u0000 Machine Learning Algorithm (Recurrent Neural Network) is used to generate the predictive maintenance schedule based on the data-driven fatigue prediction model created from the measurement data. The case study shows the life extension of the offshore jacket structure with proposed machine learning based life extension methodology.\u0000 The data-driven fatigue predictive model generates the remaining fatigue life, and it is compared with the fatigue life calculated from the FE model. It shows a good match and within 5-10% inaccuracy limit. The predictive maintenance schedule is developed based on the remaining fatigue life. ML-based model significantly reduces the computational cost as well as the real-time data also improves the fatigue life calculation accuracy. Hence, though predictive maintenance, the overall operational cost will be reduced significantly.","PeriodicalId":10927,"journal":{"name":"Day 3 Thu, October 31, 2019","volume":"5 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74298720","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":"On the Development of Technology Governance in the Well Area","authors":"Julio Cesar Sampaio do Prado Leite, M. T. Lopes","doi":"10.4043/29862-ms","DOIUrl":"https://doi.org/10.4043/29862-ms","url":null,"abstract":"\u0000 The present paper describes the establishment and implementation of the technology governance in the well area at Petrobras, which includes R&D, qualification and homologation projects. Corporate standards delineated the technology governance to assure uniformity and impersonality. It comprises two main processes: (i) establishment of technical specifications; (ii) technology evaluation. The former includes the elaboration/review of technical specifications focused on functional, quality and reliability aspects and clearly defined normative requirements. The latter process begins with the presentation of the technology by the potential suppliers and evaluation of interest by the project areas. Subsequently, in accordance with the readiness level assigned to the technology, it may be allocated as a R&D, qualification or homologat ion project, addressing to the appropriate treatment and assuring celerity for the necessary analysis.\u0000 To operationalize the whole process, Petrobras created a department in well area responsible for structuring and leading processes related to the admission of new technologies to the company, linked with the already well established R&D process. Deliberative forums have been held with managers of all the technical areas involved allowing collegial decision. Prioritized projects have been conducted by multidisciplinary working groups, including representatives from project and operation team, contract department, and also well experts. All technology process deliveries are reported by means of standard documents and are recorded in corporate system ensuring traceability and technical memory preservation. Nowadays, all the processes are well established and running for over 2 years with good feedback from stakeholders. It is worth mentioning the improvements in communication flow between and within departments and teams, better definition of roles and responsibilities reducing interface issues and easy availability of information that may be accessed for all parties involved with the projects. Additionally, there is a continuous improvement for system solutions assuring input, maintain, control and consult the whole information shared throughout the process.\u0000 The method adopted based on technology readiness level for new equipment/material/service assessment is aligned to good practices from other segments, such as aerospace industry. Moreover, technical specification focused on functional, quality and reliability requirements and system solutions for quick information availability complies with IOGP recommendations, ISO standards and with an increasingly restrictive regulation scenario especially after the lessons learned post-Macondo.","PeriodicalId":10927,"journal":{"name":"Day 3 Thu, October 31, 2019","volume":"71 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90901846","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":"Novel Solution for Cementing Operations in Scenarios of Losses and Improving Cement Bonding Results in the Brazilian Deepwater Pre-Salt","authors":"R. Freitas, L. Rossi, L. Pagani, A. Gregatti","doi":"10.4043/29758-ms","DOIUrl":"https://doi.org/10.4043/29758-ms","url":null,"abstract":"\u0000 Brazilian pre-salt reservoir is mainly composed of carbonate rocks which are naturally fractured and where severe loss of circulation has often occurred.\u0000 Loss of circulation during drilling or cementing is a serious issue that usually leads to nonproductive time, increase of well construction costs, and impairment of cement sheath quality, which may lead to deficient zonal isolation in the future and compromise well integrity in long term.\u0000 Data analysis from studies developed by operators around the world show that approximately 12% of all nonproductive time accumulated in a certain period is due to loss of circulation occurrence. In Brazil, an analysis performed by an operator in 2014, pointed that more than 100 days were lost in pre-salt wells in operations to cure or minimize loss of circulation. This same analysis concluded that more than 170 000 barrels of drilling fluid were consumed due to this scenario of losses. It is also important to emphasize the cases where a remedial cementing job was necessary due to failure of zonal isolation achievement through primary cementing, resulting in additional costs and nonproductive time.\u0000 Said that, it was important to develop and implement a new technology capable of mitigate losses during cementing operations and minimize the risk of a remedial cementing need. Since January 2017, Fibrous Loss Circulation Material has been used in the cementing jobs for production casings in the pre-salt wells successfully. Up to now, six wells were cemented using this technology; no remedial job necessary and the cementing logging evaluation showed excellent results.","PeriodicalId":10927,"journal":{"name":"Day 3 Thu, October 31, 2019","volume":"58 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88891967","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":"Uncovering the Mechanisms of Low-Salinity Water Injection EOR Processes: A Molecular Simulation Viewpoint","authors":"E. F. Martins, G. A. D. Silva, M. A. Salvador, Alvaro David Torrez Baptista, J. M. D. Almeida, C. R. Miranda","doi":"10.4043/29885-ms","DOIUrl":"https://doi.org/10.4043/29885-ms","url":null,"abstract":"\u0000 In this work, we present a multiscale approach based on first-principles calculations and classical molecular dynamics methods, to investigate the enhanced oil recovery via low-salinity water injection (EOR-LSWI). Salting-in effect, wettability, pH alteration, electrical double layer and the main geochemical reactions involved in the multicomponent ionic exchanges mechanism were analyzed in order to understand their contribution, also to provide an overall phenomenological perspective of the involved phenomena with a proposed feedback control system. The first-principles calculations were based on density functional theory, carry out in the Quantum-ESPRESSO package, to determine the adsorption energies of hydrocarbons (propionic and pentanoic acids and phenol) on calcite (CaCO3) {10.4} surface. In addition, we have obtained the free energy variations for the minerals dissolution processes. The solvent effect was taken into account for the geochemical reactions through a continuum dielectric. The interface between calcite and API brine was investigated through steered classical molecular dynamics, as implemented in the LAMMPs code to evaluate the brine ions adsorption/desorption on calcite surface and characterize the electrostatic environment in the vicinity of the calcite-brine-oil interfaces. Our results showed that the adsorption energies for the deprotonated molecules were lower than the ones for the neutral cases, highlighting the pH effect in the desorption processes. The pH also played a role in the calcite dissolution, since the free energy variation (ΔG) of the dissolution process mediated by H3O+ was lower than the ΔG for the neutral pH process. We found the lowest dissolution ΔG for the MgSO4 mineral (bulk), indicating that Mg2+ and SO42- ions would be abundant in the solution. In contrast, the other minerals exhibit a positive ΔG. Ions adsorption/desorption on calcite are isoergic and suggest an equilibrium between Ca2+ and CO32- ions. In contrast, the Na+ and Cl- ions adsorption were not found to be a spontaneous process. Moreover, the potential of mean force profile for Ca2+ and CO32- ions showed a layered structuring, which indicates that the ion hydration energy is related to the adsorption/desorption process. Such results may contribute to cause-effect understanding of correlations among the mechanisms in EOR-LSWI and help to propose an optimal brine composition to maximize the oil recovery.","PeriodicalId":10927,"journal":{"name":"Day 3 Thu, October 31, 2019","volume":"42 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83661814","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":"Effect of CO2 Injection on the Interfacial Tension for a Brazilian Pre-Salt Field","authors":"Santiago Drexler, E. L. Correia, Ana Carolina Jerdy, Leandro A. Cavadas, P. Couto","doi":"10.4043/29769-ms","DOIUrl":"https://doi.org/10.4043/29769-ms","url":null,"abstract":"\u0000 Interfacial tension (IFT) between oil and brine plays a key role in determining the capillary forces in the porous medium. When studying Enhanced Oil Recovery (EOR) methods, it is of great relevance to characterize the IFT. In the case of Pre-Salt reservoirs, CO2 and water alternated with gas injections are being considered as EOR techniques. For paraffinic oils, such as alkanes, the presence of CO2 decreases the IFT between oil and brine. However, for Pre-Salt oils with high concentrations of asphaltenes and resins, the effect of CO2 injection on the oil-brine IFT has not been reported. This work uses the drop shape analysis technique to measure the IFT between a Pre-Salt crude oil and synthetic brine with the composition of formation water in the presence and absence of CO2. The results were compared to those obtained for synthetic oil consisting of alkane and aromatic molecules. For the crude oil, CO2 dissolution, which decreases brine pH, increased the IFT between oil and brine. Oil characterization retrieved high concentration of asphaltenes and resins and considerable acid and basic numbers. In addition, infrared spectroscopy and nuclear magnetic resonance of the asphaltene fractions of the crude oil reported acid functional groups in these polar compounds. Therefore, the surface activity of the polar compounds in the oil may be reduced at lower pH. On the other hand, for the synthetic oil, CO2 decreased the IFT as previously reported for alkane molecules. Therefore, this work shows the difference in the effect of CO2 on IFT, which depends on the composition of the oil and aqueous phases. Furthermore, the acid/base characterization of the polar compounds is relevant to understand the effect of CO2 dissolution on the resulting IFT.","PeriodicalId":10927,"journal":{"name":"Day 3 Thu, October 31, 2019","volume":"17 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83474622","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":"Partnerships & Joint Ventures in Brazilian Oil and Gas Markets","authors":"M. Bastos, José Alberto Bucheb","doi":"10.4043/29841-ms","DOIUrl":"https://doi.org/10.4043/29841-ms","url":null,"abstract":"\u0000 Partnerships and JV are quite common in the Oil and Gas industry. In the offshore activity, in order to reduce the risks of capital intensive projects oil companies used cooperate entering into JV agreements. In addition, local content requirements and entry barriers in new markets, are some reasons to create partnerships between international and domestic companies. Brazil is not different. It is a market that has some challenges in which the cooperation with a local partner could reduce the risks for a foreign investor. In the oil companies’ side, Petrobras is the target partner for an international oil company, because of its technical reputation and successful implementation of ultra-deep operations. In other segments, Petrobras, can be the main client, sole supplier or big competitor. Petrobras is subject also to laws and regulations to hire contractors, there are local content requirements regulations, industry-specific tax, fiscal and customs regimes, among other risks and opportunities in which the cooperation with a domestic company could help to solve in a more efficient way. The author of this paper describes the advantages of the partnership for international and domestic companies which want to invest in Brazil in the several perspectives along the oil and gas supply chain.","PeriodicalId":10927,"journal":{"name":"Day 3 Thu, October 31, 2019","volume":"30 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72649921","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":"Electrocoagulation Treatment for Reverse Electrodialysis Wastewater from Petroleum Refinery","authors":"F. Gonçalves, Dhayannie Hellen Galdino Duarte Tocafundo, André L. Santos, Elbert M. Nigri, S. Rocha","doi":"10.4043/29911-ms","DOIUrl":"https://doi.org/10.4043/29911-ms","url":null,"abstract":"The present study investigated an evaluation efficiency of electrocoagulation (EC) for the pretreatment of a saline concentrated effluent from the reverse electrodialysis (RED-C) stage from an oil refinery, aiming at water reuse in the industrial process. In this approach, an electrocoagulation system with 1 L capacity was set up for batch treatment using aluminum electrodes. Initially, experiments with a semi-synthetic RED-C effluent were assessed for contaminants removal using fixed current density of 8.30 mA/cm2 and 1 cm distance between electrodes. The influence of initial pH (5 and 7), controlled temperature (20, 30 and 40°C) and operation time (60 and 120 min) on removal efficiency was investigated and solid residue were measured. The results showed that the optimum conditions were at pH 7 and 20-30°C with removal rates around 70%, 57%, 10% and 44% for Ca, Sr, Na and COD, respectively. Thereafter, experiments were conducted with a real RED-C using the best condition founded in preliminary tests, this time applying a current density of 5 and 10 mA/cm2 and 0.5 cm distance at room temperature (approximately 23°C). Regarding the tests with real RED-C, for both current densities the removals were greater due to decrease in distance between electrodes and larger temperature range that improved electrocoagulation. In general, the use of current density of 10 mA/cm2 and reduction of inter-electrode distance increased EC efficiency which exhibited removal rates of 88%, 77%, 26% and 24% for Ca, Sr, Na and COD, respectively. Although, it was observed a decrease in COD removal from real RED-C due to the addition of inorganic ions in the semisynthetic effluent that precipitated as salts, removing more organic as a coadjuvant compound. The solid slugde production for this same condition were 5.65 g/L.","PeriodicalId":10927,"journal":{"name":"Day 3 Thu, October 31, 2019","volume":"85 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75031203","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":"Pseudo-Sticking and Pull – A New Old Artifact on Image Logs Acquired in Ocean Wireline Log Operations","authors":"Sofia Alves Fornero, Lenita de Souza Fioriti, A. P. C. Laier, Gabriel Da Silva Felipe","doi":"10.4043/29935-ms","DOIUrl":"https://doi.org/10.4043/29935-ms","url":null,"abstract":"\u0000 The \"pseudo-sticking and pull\", also nicknamed \"blocky effect\" (because of its general aspect), is a common acquisition artifact that reduces considerably the quality of wireline acoustic and microresistive image logs, even though it is not well known among image log interpreters, well-site geologists and engineers. This artifact is generated by heave motion influence when the wave movement is not minimized enough by the compensation systems during offshore wireline operations. In fact, it is well known that the linear or rotary compensator systems reduce the heave variance between 52-80% and, sometimes, other factors such as string weight and fluid density can affect, significantly, wireline logs quality by the heave variance not well compensated. In this case, mainly the wireline stationary tools and the ones that need lower acquisition speed, present depth uncertainties that may cause relevant problems. The image logs are largely used in pre-salt reservoirs for geomechanics, petrophysics, structural, sedimentological and stratigraphic studies due to their great contrast responses on carbonates. However, because acoustic image logs run at speeds around 425 ft/h (against 3600 ft/h from basic logs) and acquire between 180 and 250 samples data each 0,2 inches depth, this log becomes more affected by this artifact than the microresistive one (over 1500 ft/h). The residual heave affects directly the image quality by creating \"pseudo-sticking and pull\" at each wave period, distorting the image log significantly. Besides the artifact that immediately appears on the image during the logging, the residual heave can also be confirmed by observing when cable tension and vector Z accelerometer variation have the same frequency as the period of ocean waves, monitored by the meteo-oceanographic daily reports. Even though this artifact can be minimized with processing (better than true sticking and pull corrections), the loss of quality should be considered. Petrobras experience has also shown that interventions directly on the source by adjusting compensators and changing steering towards can be effective to handle this problem. In order to help the interested community in acquiring better data with minimum costs, this work shows some examples of this artifact on acoustic image logs from pre-salt wells. It can also show the results with processing, the differences reached after adjusting compensators and demands for future works.","PeriodicalId":10927,"journal":{"name":"Day 3 Thu, October 31, 2019","volume":"47 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79978871","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}