bluuebunny/crossref_metadata_2025_split huggingface dataset:
Quantification of Oil Recovery Mechanisms during Gas Injection EOR Coreflood Experiments
Authors: Wanat Ed , Teletzke Gary , Newhouse Dan , Lawrence John , Shehhi Rashed Al , Willingham Thomas , Jawhari Mohammad Omar 
Published: November 2017

Abstract
This paper presents results of gas injection enhanced oil recovery (EOR) core flood experiments to highlight mechanisms of oil production throughout the life of an EOR project. The relative contributions of vaporization and condensation/swelling production mechanisms are quantified by analyzing the compositional results of a series of gas flood experiments conducted with live fluids at reservoir temperature and pressure and a variety of gas injectants including CO2 and various hydrocarbon gases. The compositional information is useful for calibrating tuned equation of state (EOS) and gas flood simulation models, thus enhancing confidence in field-scale performance predictions.
When analyzing results from such gas floods, care must be taken to properly account for changes in oil composition. Using the black oil assumption, the composition and formation volume factor (FVF) of the oil produced throughout the gas flood is assumed to be constant. The consequence of this assumption can lead to inaccurate estimates of oil recovery. To overcome the limitations of the black oil assumption, we introduce a rigorous methodology to account for changes in oil composition. A tuned 10-component EOS, is used to reconstruct the produced fluid compositions, measured at laboratory conditions, back to reservoir conditions. Conversion of detailed oil composition measurements to the 10-component compositions used by the EOS while honoring the weight fraction composition measurements is accomplished using a gamma probability distribution function.
As expected, gases with lower minimum miscibility pressure (MMP) recovered a higher percentage of remaining oil in the core. In addition, the reconstructed reservoir-conditions compositional data revealed especially useful information for understanding the physical processes involved in oil recovery. The weight fraction of produced components as a ratio of the weight fraction of that component present in the original live oil was especially illustrative. Significant differences in the relative contributions of the vaporization and condensation/swelling mechanisms were observed depending on how close the reservoir oil was to its saturation pressure. Finally, results of history matching the gas flood experiments using compositional simulation confirm the results seen in the laboratory data.
Unlocking Bypassed Oil in Mature PDO South Oilfields by Developing Gharif Low Resistivity Pay
Authors: Mahaldar S. , Mandhari S. , Jorgensen W. , Busaidi H. , Saadi H. , Yaarubi A. H. 
Published: November 2017

Abstract
PDO has a large portfolio of mature Gharif fields with significant hydrocarbon potential to be unlocked by efficient well and reservoir management (WRM). In 2016, focussed surveillance on Closed-in Wells (CIW) in a mature PDO South Gharif field, highlighted significant bypassed oil opportunity in Low Resistivity Pay (LoRP) reservoir –"C". Presence of conductive minerals and different clays in the LoRP sands, led to a pessimistic assessment of resistivity based hydrocarbon saturation. As such, histrocially, these oil bearing sands were not perforated. LoRP was production tested in 2 CIW & 3 New Oil (NO) wells in 2015, doubling field's net oil production (Figure1). Insights from historical field production, pressure depletion, core and Nuclear Magnetic Resonance (NMR) data were integrated to update the static subsurface model which led to an increment of 21% in the field STOIIP.
Current inventory of high water cut (&gt;95%) and high sand producing oil producers are being converted to dedicated LoRP producers on opportunity basis. This has reduced the frequency of expensive well workovers. Quick screening of LoRP has been initiated for all PDO South fields. Initial results show that similar bypassed oil opportunities exist in other mature brown PDO South fields as well. Broadly speaking, such bypassed oil opportunities can be attributed to one of the following subsurface mechanisms at play i.e. presence of thin sand- shale intercalations which are not vertically resolved on wireline logs, presence of condutive minerals e.g. pyrites or clays and high irreducible water saturation in microporous rocks.
With the current low oil prices, re-exploration of mature fields by interpreting and maturing low resistivity pay reservoirs, presents an attractive business proposition.
Corrosion Control in Sulphur Recovery Units – Claus Process
Authors: Alkasem A. , Slavens A. , Dhinda H. , Berrouk A. S. 
Published: November 2017

Abstract
Today there are more than 100 Sulphur Recovery Units in the Middle East and many of them have been in operation for 10 years or longer. Corrosion can be one of the most challenging issues in these units due to the presence of hydrogen sulfide, sulphur dioxide, elemental sulphur and water. If operated within the normal operating temperature range, corrosive conditions should not occur; however, if upset conditions result in temperatures which are too high or too low, several corrosion mechanisms are possible. This issue has resulted in many instances in which existing units have been forced into emergency shutdown for several days to perform maintenance. This results in production loss and the potential for significant environmental impact due to flaring acid gases.
API 571 documents most of the major corrosion mechanisms in the Claus process such as sulfidation, oxidation, flue gas dewpoint corrosion and wet sulphur corrosion. However, it does not address specific means of controlling corrosion, taking into account different technologies available for tail gas treatment.
This paper demonstrates the fundamental corrosion issues encountered in SRUs and proposes protective actions. Guidance related to start-up, shutdown and normal operation is also provided for establishing appropriate operating limits to achieve safe and reliable operation for corrosion avoidance.
This paper takes a unique approach which considers both theoretical and practical, real-world experience in the mitigation and monitoring of corrosion control. Operators are provided with tangible recommendations that can be applied to their facilities. Protection against atmospheric corrosion is not in the scope of this paper.
This paper has been prepared based on a review of several industry publications, which address specific corrosion mechanisms in SRUs. The main objective of this paper is to provide a high-level overview of these works, while also offering guidance on the safe operating envelope of the facility, to avoid excessive corrosion. Most of the metallurgy in an SRU is typically specified as carbon steel, which is adequate when the unit is operated within safe operating limits. However, if operated outside the acceptable range (above or below), corrosion can be swift and severe, as will be described.
Delineation of Fracture Clusters by Integrating Tectonic Events, Seismic Attributes, BHI Interpretation, Mud Losses during Drilling and Well Test Data – A Case Study in a Carbonate Reservoir, Offshore Abu Dhabi
Authors: Hou Lian , Lavenu Arthur P. , Xi GuiFen , Al-Kaabi Ahmed Saeed , Van Kleef Franciscus , Lecoq Thierry Francis , Al Blooshi Asma Mohamed 
Published: November 2017

Abstract
Faults and fractures play an important role in reservoir production, since they can act either as barriers or conduits for fluid migration. They are also one of the key factors to be considered for drilling trajectory design. However, it is very challenging to delineate fractures due to the limitation of seismic resolution. The objective of this study was to conduct fracture cluster characterization for one of the carbonate reservoirs in Abu Dhabi, using a recently acquired 3D seismic survey.
In this study, the similar workflow used by Singh et al. (2009) was followed. First of all, structural evolution and regional paleo including current principal stress orientations were investigated. Three major tectonic events were identified, and they are the main contributors to the development of faults and related fractures. Secondly, seismic data was processed based on an objective-driven processing sequence. Three fracture volumes were generated and five sets of fractures were interpreted. They were validated against the regional principal stress orientations, BHI interpretation, mud losses and well test data.
In addition, previously the discontinuities along NNE-SSW direction in the area of interest were considered as seismic acquisition footprints. Through this study, it was proved that those discontinuities are small scale faults, hereby enhanced the existing reservoir characterization.
The findings on faults and fractures characterization in the study area are critical in field development plan and drilling efficiency. This study showed that integrating data from different disciplines is a reliable and effective way to delineate fracture clusters.
Acquisition of Satellite Derived Bathymetry Data for Offshore Engineering Projects - Island Case Study
Authors: Athmaram Jayaprakash , Srinivasan Ashish GS 
Published: November 2017

Abstract
Recent advances in satellite technology such as improved image resolution and use of multi-spectral bands have increased its potential as an alternative source of hydrographic data. Recent applications in the surveying industry have proved the usefulness of Satellite Derived Bathymetry (SDB) as a low cost source of good quality bathymetry data. In order to support ADNOC's efforts to fast track new field development projects and timely delivery of high value data, ZADCO as part of its survey campaign selected SDB as a tool to source quality near shore hydrographic data.
Offshore bathymetry derivation was realized using WorldView-3 satellite scenes. These scenes were processed by following a rigorous processing methodology for the correction of atmospheric adjacency. The processed and corrected satellite image provided a spatial resolution of nearly four metres and covered depths from the 0m depth contours up to the 15m depth contours. The accuracy and reliability of the satellite images are dependent on the optical conditions of the satellite scene, the sensitivity of the satellite's sensor and the accuracy of the calibration.
After detailed multi-level quality checks for various systematic and non-systematic errors, the most reliable bathymetry that was found to meet ZADCO selection criteria was noted to be between 0m and 3m water depths, with an error of ±0.3m. Water depths between 3m and 5m presented themselves with an error of ±0.4m, whereas for depths between 5m and 10m, the errors varied between 0.5m to 1.0m. It was found that in the extreme nearshore areas with depths between 0m and 3m water depths, SDB could be accepted for use as it was falling within the tolerance limits of ±0.3m, with most areas having a tolerance of ±0.2m. While satellite derived bathymetry between the 0m to 5m water depths was found to be of acceptable quality, those over drying heights were found to be completely unreliable.
The reliability factor that could be established for SDB data between 0m and 3m implied that dangerous and logistically challenging nearshore survey operations using conventional methods, that is, using shallow draught survey motor boats could be done away with. This also presented an interesting corollary in that it can also remove a huge HSE risk factor associated with shallow water survey boat operations, which are otherwise a significant risk due to the presence of underwater obstacles such as corals, rocks, reefs and surface dangers such as wave action and tidal influences.
In conclusion, high resolution multi-spectral satellite imagery corrected for atmospheric and underwater refraction effects combined with the correct processing techniques and multi-level quality control mechanism provides a reliable source for bathymetry in extreme nearshore areas. Based on the results achieved it was concluded that SDB data can be used for engineering planning and estimation applications, for quick turnaround.
Hybrid Multi-Stage Acid-Fracturing in Deep Carbonate Gas Wells with HTHP in Anyue Gas Field of Sichuan Basin, SW China
Authors: Suzhen Li , Yun Xu , Yujin Wan , Mingguang Che , Liao Gao Yuebin , Zhanwei Yang , Rui Gao , Xinwei Lu , Lang Zhou , Yezhong Wang , Weihua Chen , Hao Zhou 
Published: November 2017

Abstract
The naturally fractured Anyue Gas field contains Longwangmiao (Cambrian) and Dengying (Sinian) formation. The oldest age formations were formed large-scale marine carbonate gas reservoirs with buired depth from 4500m to 5500m, temperature of 150°C and pressure coefficient of 1.6. Approximately one-third of wells cannot reach the economic production because of serious reservoir heterogeneity; therefore, a novel hybrid acid-fracturing technique was applied to enhance the gas production by increasing stimulated reservoir volume. Hybrid multi-stage acid-fracturing technique was used to the reservoirs with poor connectivity between vugs and fissures. Large quantity slick water with 100 mesh proppant as pad was injected with high pump rate to reduce sand plug risk and form shearing fractures,and then ground cross-linked acid and gel acid were injected alternatively to corrode the fissures far away wellbore to form fracture network.
It is the first time that hybrid multi-stage acid-fracturing technique was used to stimulate the low permeability and low porosity carbonate gas reservoir with poor connectivity between vugs and fissures in China. The introduction about this technique will provide some reference for the stimulation design in the similar reservoirs in spite of the non-ideal stimulation result.
Forty Years of AlMansoori Focused Workforce Engagement. A Catalyst for Customer Value, International Growth, Profitability with Happy Clients and Happy Employees!
Authors: Al Alawi Ibrahim , Kuijken Chris 
Published: November 2017

Abstract
This paper describes the successful staff engagement strategies underpinning the leadership and continuous transformation journey of the 100% UAE Company AlMansoori whereby a slickline services start-up company in the year 1977 in only one geographical location (Abu Dhabi) transformed into a large conglomerate covering upstream and downstream businesses in oil, gas, chemicals, manufacturing and supporting services.
Offshore Pipeline Failure Root Cause Analysis
Authors: Iyeh Emmanuel , Adams Grant 
Published: November 2017

Objective/Scope
The objective of this study was: ▪To evaluate potential causes of failures of several (9) pipelines operating in shallow waters 8m to 14m water depth in the Gulf of Guinea and develop an analysis / programme to identify the root cause of failure.▪Perform analysis to confirm the causes of failures,▪Assess remedial measures to find the most suitable remedial option,▪Recommend remedial measures to prevent future pipeline failures,▪Perform high level engineering to confirm suitability of chosen option
These studies and assessments have been performed in accordance with API RP 1111 and DNV RP F109. From 2009 to 2016 several pipelines failed in this region (shallow waters 8m – 14m offshore Nigeria) in the Gulf of Guinea, resulting in a huge amount of deferred production (deferred revenue). To forestall future occurrence, this study was performed to identify the root cause of failures and provide recommendations to mitigate these failures in both existing pipelines and future pipelines (in design) operating in such environment.
Deblended-Data Reconstruction for Time-Lapse Seismic Monitoring
Authors: Ishiyama Tomohide , Ali Mohammed , Blacquiere Gerrit , Nakayama Shotaro 
Published: November 2017

Abstract
We introduce a generalized concept of the so-called blending and deblending, and establish the generalized-blending and -deblending models. Accordingly, we establish a method of deblending, or deblended-data reconstruction, using these models.
The generalized blending can handle real-life situations; this includes random encoding both in the space and time domain, both at the source and receiver side, thus all incoherent shooting, inhomogeneous shooting, non-uniform and under sampling. Similarly, the generalized deblending includes data reconstruction that works for all shot-generated-wavefields separation, spectrum recovery and balancing, regularization and interpolation, again both at the source and receiver side. However, we do face a challenging question: how to fully reconstruct deblended data from the fully generalized blended data. To address this challenge, we consider an iterative optimization scheme using a so-called closed-loop approach. We use the properties of blended signal specified by the blending code: the coherency of blended signal versus the incoherency of blending noise in the pseudo-deblended domain. This can be posed as an inverse problem with quantifying the coherency and its solutions by selecting optimal metrics of the coherency. We applied this method to synthetic datasets. The results show that our method succeeded to fully reconstruct deblended data from the fully generalized blended data.
We discuss its applicability to time-lapse seismic monitoring as it ensures high repeatability of the surveys. Our methodology should reduce the repeatability problem because reconstructing deblended data in monitor surveys is much more realistic and reliable than positioning sources and receivers exactly as the baseline survey.
Expandable Liner Deployment Remedies Premature Casing Point in an Offshore Gas Well
Authors: AlMusa Abdulaziz S. , Obi Ikenna I. , Garcia Joaquin S. 
Published: November 2017

Abstract
Offshore deep gas wells in Saudi Arabia present diverse challenges for drilling that must be overcome to reduce non-productive time. The nature of deep well design dictates multiple casing strings that require long drilling sections through problematic zones. The objective of arriving to the designated casing point is crucial to avoid jeopardizing the well requirements. Expandable liners have proven to be a viable solution that was implemented in offshore field X in Saudi Arabia.
Field X is a challenging field in which numerous geological formations are troublesome. In order to meet completion size requirements, long drilling sections are required that combine different problematic zones. Even though the casing design takes into consideration these problems, the risks are still present. Lost circulation is one of the most prominent issues that have been tackled through different methods. Depending on the scenario, there may be cases where a section is terminated due to the severity of lost circulation and the casing is installed at a premature depth. Expandable liners provided a solution to this scenario.
The case that will be discussed is an implementation of expandable liners in well X-1. Lost circulation was the main reason for terminating the casing point shallower than what was required. Even though significant efforts were made to cure the losses, the situation necessitated to conclude the section. The expandable liner implementation salvaged the remainder of the section whilst preserving the casing size rather than resorting to slim down the well design. Consequentially, this prevented further complications in subsequent sections avoiding further expense and NPT.
The value of this method lies in its robust solution to premature casing points where it resumes the well to its original plan.
Post-Stack Seismic Merge: A Case History, a Pathway for a Desirable Survey Overlap
Authors: Mahgoub Mohamed , Hagiwara Hiroshi , Hammadi Yousif Al , Matarid Tarek , Hindi Hani Bu 
Published: November 2017

Abstract
Merging 3D seismic surveys into a seamless single 3D volume, either post-stack stage or pre-stack stage, is a challenging task on seismic data processing. This study describes some tips from coastline Abu Dhabi where we successfully managed merging two partially overlapping surveys during post-stack stage, one from transition zone (land and shallow marine) while the other one from offshore 3D OBC seismic survey, in order to understand subtle geological structure relationship among two areas. Since spatial sampling between two surveys are greatly diverse due to different orientations and grid sizes, a conjugate grid which is identical to a main cube had been applied over the subordinate one that enable the whole dataset to interpolate and process as a same grid. Then we deployed pre-conditioning steps over the subordinate dataset to minimize their quality differences where we particularly focused on residual noise, multiples, frequency contents and event timings. Lastly, a matching filter was designed and applied to the subordinate side to compensate residual amplitude, frequency and phase and produce a final dataset for structure interpretation.
A single consolidated seamlessly merged volume was produced throughout the steps as described above along with well-to-seismic calibrations. Seismic interpretation was conducted over the main reservoir between two datasets/fields with a good degree of confidence. The present day structure separation and structure growth history were analyzed as a part of the structure interpretation. Moreover, this case study illustrates the add values of the seismic 3D merge from the aspect of regional structure restoration, and revealing structure relationship between the overlapping surveys. The final merging result outcome of this case study has an amenable structure continuity and seamless horizon mapping of the common reservoir target level between the two surveys. Additionally, the merged seismic cube did showcase a lateral zero phase wavelet stability of the existing wells that verified the reliability of the conducted post-stack seismic merging processing workflow. This case study has successfully demonstrated and summarized key technical tips that are recommended for merging datasets on post-stack domain in the future. However, pre-stack merge is also and still strongly recommended since static corrections, velocity pickings and imaging processing can be applied throughout the two surveys in one go while these cannot be fixed on post-stack merge. From data acquisition perspectives; enough overlap to reaching the full-fold rim of the overlapping surveys is highly recommended.