bluuebunny/crossref_metadata_2025_split huggingface dataset:
Completion Optimization while Drilling – Geomechanical Steering towards Fracable Rock for Optimal Selection of Stage Spacing and Cluster Density in Unconventional Wells
Authors: Ouenes A. , Dirksen R. , Paryani M. , Rehman S. , Bari M. 
Published: June 2017

Abstract
The drilling of thousands of unconventional horizontal wells in North America highlighted the impact of the landing zone on production, underscoring the importance of geosteering with the intention of staying in the most fracable rock. Unfortunately, the use of fast drilling motors combined with delayed logging tools, and insufficient data to quantify mechanical properties while drilling created multiple geosteering challenges. This paper describes a new technology that uses surface drilling data to estimate, in real time, the geomechanical properties needed to guide the steering of horizontal wells into the most fracable rock.
The Mechanical Specific Energy (MSE) computed from commonly available drilling data such as torque, rate of penetration and weight on bit has been widely used to improve drilling efficiency. However, the more recent use of MSE for completion optimization has yielded conflicting results. This paper introduces the use of Corrected Mechanical Specific Energy (CMSE) where the friction losses along the drill string and wellbore are computed and accounted for in real time. CMSE is used to estimate, in real time, geomechanical logs and build a live geomechanical model that is used for steering into the most fracable rock. Once the drilling is completed, the frac stage spacing and cluster density is adjusted according to CMSE outputs which include pore pressure, stresses, and natural fracture index.
The new approach was used on multiple shale wells where the geomechanical logs predicted from CMSE and subsequently estimated fracture index were validated with multiple data including image logs, microseismic, and elastic properties derived from seismic pre-stack elastic inversion.
This technology represents a major step in completion optimization since it tackles the problem and provides the solution during the drilling phase. A major advantage of the new technology is its ability to be deployed on any rig without the use of additional surface gauges, sensors or downhole measurement tools, avoiding additional costs and risks of potential wellbore problems. Additional benefits of the technology include: no on-site personnel or permits, the use of existing real time drilling data streaming services to quickly steer in the fracable rock, and having completion design immediately following the completion of drilling. This contrasts dramatically with alternative completion optimization methods for which data delivery, analysis, planning and design can take many weeks.
Modelling Temporal and Spatial Sedimentary Architectural Complexity in Mixed Aeolian-Fluvial Reservoir Successions
Authors: Al-Masrahy Mohammed 
Published: June 2017

Abstract
Studies of modern desert dune fields allow geologists to draw conclusions about the controls that govern the development of spatial patterns of arrangement of desert landforms. This knowledge can be applied to predict the likely arrangement of architectural elements in preserved ancient desert successions. This serves as the basis for the development of more sophisticated facies, architectural-element and sequence stratigraphic models that can be applied in reservoir geology.
This study presents a series of ten bespoke facies models that demonstrate different types of aeolian-fluvial interaction documented from dune-field margin settings. These ten semi-quantitative models have been developed based on analysis of modern and ancient systems, and via comparison of literature-derived case-study examples of ancient successions using a meta-analysis approach. The presented facies models account for the nature and origin of stratigraphic complexity present in aeolian dune-field margin successions that arose in response to the combined interplay of a series of autogenic and allogenic controls.
From an applied perspective, mixed aeolian and fluvial successions are known to form several major reservoirs for hydrocarbons, including the Permian Unayzah Formation of Saudi Arabia. However, quantitative stratigraphic prediction of the three-dimensional form of heterogeneities arising from aeolian and fluvial interaction is notoriously difficult: (i) interactions observed in one-dimensional core and well-log data typically do not yield information regarding the likely lateral extent of sand-bodies; (ii) stratigraphic heterogeneities of these types typically occur on a scale below seismic resolution and cannot be imaged using such techniques.
Understanding the nature and surface expression of various types of aeolian and fluvial interaction, and considering their resultant sedimentological expression, is important for prediction and interpretation of preserved deposits of such interactions that might be recognized in the ancient stratigraphic record. Assessment can be made of the spatial scale over which such interactions are likely to occur and this has applied significance; the developed facies models facilitate the prediction of net reservoir sandbody dimensions from subsurface successions by constraining the geometry and lateral and vertical connectivity of sand bodies for specific desert system types. Assuming layer-cake correlations between neighbouring wells within stratigraphically complex reservoirs composed of mixed aeolian and fluvial facies is inappropriate; instead, a range of bespoke facies models should be utilized, each of which considers possible stratigraphic configurations and each of which has implications for likely reservoir performance.
The Role of Drilling Azimuth on Wellbore Geomechanical Instability in a Major Offshore Field
Authors: Aljubran M. J. , Alsalman M. A. , Al-Yami A. S. , Ghazal M. A. 
Published: June 2017

Abstract
Saudi Aramco workover re-entry operations within Khafji sand stringers are widespread across Zuluf field. These horizontal sidetracks maintain maximum reservoir contact and introduce substantial increases in oil production and ultimate recovery. Wellbore instability is a hot topic surrounding these operations due to the presence of geo- and hydro pressurized shale within the reservoir. The in-situ stress regime in this field is predominantly strike-slip faulting and the drilling azimuth represents a dominant stability component.
The current study analyzes 58 laterals sidetracked across the Khafji formation across Zuluf field, and the effect of the drilling azimuth on wellbore stability. All laterals were cut across 7 in. casings and drilled as 6-1/8 in. open hole, with an average of 4,200 ft. in length. To accurately evaluate these data, the azimuth plane was divided into four angular regions, with respect to the maximum and minimum principal horizontal stresses: maximum stress (17 laterals), transitional maximum stress (12 laterals), transitional minimum stress (14 laterals) and minimum stress (15 laterals). Stuck pipe and severe tight-hole problems are mainly addressed for this purpose, as they are the main wellbore instability signs in this case.
The descriptive correlational approach showed that nearly 63% of the total stuck pipe and lateral abandonment incidents occurring due to shale bedding and instability, were actually along the minimum horizontal stress. Furthermore, 53% of the laterals drilled along the minimum horizontal stress experienced wellbore shale instability with either stuck pipe or severe tight holes. Hence, the findings confirm the sensitivity of wellbore stability to the drilling azimuth in strike-slip regions. They also suggest a statistically significant correlation between laterals drilled along the minimum principal horizontal stress and wellbore instability problems across Khafji reservoir in Zuluf field.
This paper will further highlight the descriptive correlational method, examine the observed wellbore instability problems, and compare the findings to previously conducted laboratory tests and geomechanical simulations.
The Application of Water Shut-Off Technique in Jidong Oilfield
Authors: Zhang Guowen , Qian Jie , Shen Zejun , Zhang Weiping , Xue Jianjun , Huang Peng , Liao Chenlong 
Published: June 2017

Abstract
Most of horizontal wells was completed with uncemented screens to prevent from sand production in some oilfields near Bohai Bay east China. In recent years oil production of the wells have begun to decline due to water out of the wells, especially water rates in part of the wells were more than 98%. Finally higher water out resulted in the wells to be closed. A technique of water shut-off was developed. First of all, a tools string for chemical agent injection (TSCAI) was run into the wellbore. The chemical agent was injected into the annular space between the screens and the formation to form annular chemical packers (ACP). So the ACP could separate the formation into several sections to avoid annular communication. Secondly, a liner hanger with sliding switches and swelling packers (LHSSP) was run after TSCAI was pulled out of the well. The liner hanger was released after the packers were set. Finally a mechanical on-off element for the sleeves with coiled tubing string (ESCTS) was run to open\close the switches separately. By analyzing the well production date the operators determine that which layer water ed out. The ESCTS was run to closed water out layer. Well-A was a horizontal well drilled in 2006 in the Gaoqianbei zone of Jidong Oilfield. In 2010 production logging date showed that water content was 98.7%. A water shut-off action was done. The whole horizontal interval was separated three sections (No.1, No.2, No.3 layer). Finally after No. 1 layer was confirmed to be water cut layer to be closed, daily oil production was improved from 2 tons to 4 tons. Water content reduced to 70.9%. Generally, the successful water shut-off for well-A showed that the technique could efficiently enhance oil recovery with simple operation and low cost. It provides a new water shut-off method for other wells with different completions.
Flowing Gels for Loss Circulation Prevention
Authors: Hashmat M. D. , Sultan Abdullah S. , Rahman Saifur , Hussain S. M. , Ali Shaikh Asrof 
Published: June 2017

Abstract
Loss circulation is a common problem in drilling operations. It is a problem in which not only the valuable drilling fluid is lost, but also time and money accompany those losses. In order to mitigate this problem various loss circulation materials (LCMs) are being used all over the world. Among those LCMs are crosslinked polymer gel systems.
In this work, a polymeric LCM system was studied for its potential use as a loss prevention material. The system studied is composed of polyacrylamide (PAM), phenol and formaldehyde as the main components. Under certain temperature and mixing conditions, their interaction constitutes a strong flowing gel. To study the effectiveness of the system, the gel was tested into a self-fabricated see through flow apparatus to study the effectiveness of the gel system in preventing mud losses under different permeability conditions.
The crosslinked polymeric gel system was tested under three different permeability conditions. It was observed that the gel system was effectively able to prevent losses in two of those porous media at room temperature and moderately high-pressure conditions. Of these, the least permeable thief zone had a porosity of 36% and a permeability of 300 D. The same porous media was selected to study the behavior of the gel with respect to time. For this experiment a bulk volume of the gel was prepared and left static in the LCM displacement vessel. The flow experiment was conducted at three different timelines. It was observed that with the passage of time the gel system gets denatured but still remains relatively effective.
This paper will highlight and add to the usage of crosslinked organic polymer gelants as LCMs. It will present the findings of an in-house see through flow setup that was used to study the effectiveness of the LCM in relation to the differential pressure across the loss zone.
Open Hole Washout Maneuvering Technology Using Coiled Tubing
Authors: Al-Hajri Nasser M. , Al-Ajmi Mohammed D. , Al-Subaie Fehead M. , Al-Meshal Fahad M. , Al-Shammari Nayef S. 
Published: June 2017

Abstract
This paper will present a Coiled Tubing (CT) technology that can be used to maneuver severely washed-out open hole sections. The presence of open hole washouts is known to restrict access to pay zones during reservoir monitoring or other well intervention operations. The case study of the paper is a water injector completed with a 6-in. open hole across the pay zone. The lithology of the first 30 ft of the open hole section contains anhydrite. Due to prolonged exposure to injection water, leaching of the anhydrite layers took place. This has led to the creation of washout. The washout has been confirmed to be present below the casing shoe by analysis of a caliper log.
A prior attempt to access the open hole with CT was not successful. Accordingly, several Bottom Hole Assembly (BHA) designs were thoroughly examined to determine the appropriate CT deployment tool and carry out a planned acidizing work on the water injector well. The contemplated BHA designs were initially planned to include conventional well intervention tools or a combination of these tools such as knuckle joints, straight bars, and a hydraulic centralizer. However, these tools were ruled out due to their previous failure to access the wellbore in the case study well (knuckle joints and straight bars) or the risk of CT being stuck in the open hole (hydraulic centralizer).
After a careful consideration of all relevant parameters to the acidizing work, an open hole washout maneuvering technology was deployed. The CT conveyed technology consisted of a torque through knuckle joint, mechanical rotating tool and a bended sub. The deployment of this innovative technology was successful in passing the abovementioned washout. The CT successfully reached the well total depth and the benefits of this technology were fully realized as the open hole section of the reservoir was entirely exposed to the acid treatment
A Novel Approach to Formulation of Emulsified Acid Using Waste Oil
Authors: Sidaoui Ziad , Sultan Abdullah S. , Brady Dominic 
Published: June 2017

Abstract
In matrix acidizing, the aim is to create long conduits (wormholes) inside the reservoir formation which ultimately results in productivity increase. Acid in oil emulsion is used in the industry for stimulating carbonates with diesel commonly as the oil phase and hydrochloric acid (HCl) as the acid phase. Emulsifying HCl has numerous benefits over regular HCl. Perhaps the main benefit is deep penetration near the wellbore. Also, less corrosion damages are caused since the external phase is hydrocarbon (diesel). Several studies showed the success of replacing diesel as an external phase with other hydrocarbon oil, such as crude oil and xylene.
This work utilizes the extra hydrocarbon left unused –or sometimes dumped– from refineries, referred to as waste oil. The chemical composition of waste oil is studied. The HCl-waste-oil emulsion is prepared using 15 wt% HCl with a ratio of 70:30 of acid-to-oil. This paper reports results on the thermal stability and rheological properties of the HCl-waste-oil emulsion. All thermal stability experiments are conducted at a high temperature, 120 °C.
The results show that the HCl-waste-oil emulsion is a shear-thinning fluid. Power-law model is applicable seamlessly to all of the apparent viscosity data for all measured temperatures. The optimum conditions are found to be; 0.5vol% and 600 rpm for emulsifier concentration and mixing speed, respectively. Overall, the lab results show a promising potential for the HCl-waste-oil emulsion to be used in the field.
This work takes into account; reducing the budget of acidizing job along with environmental concerns. Apart from using low emulsifier concentration and low mixing speed, it makes use of the unwanted hydrocarbon from refineries.
Injection of Polymer for Improved Sweep Efficiency in High Temperature High Salinity Carbonate Reservoirs: Linear X-Ray Aided Flood Front Monitoring
Authors: Hashmet Muhammad Rehan , Qaiser Yemna , Mathew Eric Sonny , AlAmeri Waleed , AlSumaiti Ali M. 
Published: June 2017

Abstract
Polymer flooding is one of the most commonly used techniques to improve oil recovery; however its application is dependent on the technical and economic feasibility along with the knowledge of the risks involved. The presented work is focused on quantifying the uncertainties affecting the mobility of injected fluid in polymer flooding along with a sensitivity analysis of influential parameters. Initially, a coreflooding experiment on carbonate core sample is performed using partially hydrolyzed polyacrylamide, SAV 10 under high temperature high salinity conditions. The coreflood apparatus is aided with linear X-ray in order to record real time saturations for the entire length of core sample in addition to the pressure and production data. The experimental data are then history matched using commercial software to generate relative permeability curves and to optimize polymer slug size and initiation time. The optimized model is then used as a reference and a coredflood is conducted on the optimized conditions i.e. slug size and initiation time. The recovery obtained from the experimental run is compared with the simulation results. Polymer viscosity, adsorption on the rock surface and mechanical degradation are some of the other parameters included in the study. The optimum polymer flooding scenario established in this study is injection of 0.1 PV of polymer after 0.3 PV water injection. Encouraging results are obtained at the optimized conditions resulting in an overall recovery factor of 84% and early injection of polymer also helped to delay the breakthrough time. The small slug size resulted in low adsorption and residual residual factor for the optimized case is found to be 1.73.
Evaluating Feasibility of Hydrophilic Silica Nanoparticles for In-Situ Emulsion Formation in Presence of Co-Surfactant: An Experimental Study
Authors: Patel Akshit , Nihalani Dipesh , Mankad Dhaivat , Patel Dhaval , Chaudhari Ravi , Dhameliya Mehul , Tripathi Dutt , Bhui Uttam K. 
Published: June 2017

Abstract
Recent experimental studies on nanoparticles based enhance oil recovery (Nano EOR) have shown that silica nanoparticles have great ability to form Pickering emulsion, thereby increasing the ultimate oil recovery. However, the main challenge is to stabilize silica nanoparticles in reservoir's harsh conditions. Azadgoleh et.al. (2014) found that the use of anionic surfactant can increase the stability of nanofluid by imparting steric hindrance to the silica nanoparticles. In order to analyze the effectiveness of Nano EOR, it is critical to study the in-situ emulsion formation capability of stabilized silica nanoparticle in presence of surfactant especially.
Water in oil micro emulsion studies were carried out for two different types of crude oil i.e. light oil and paraffinic oil. For each crude oil, nanofluid were prepared by dispersing 0.05wt% silica nanoparticles in synthetic brine (NaCl) of different five salinities (0.1 wt.%, 0.5 wt.%, 1 wt.%, 2 wt.% and 3 wt. %). Anionic surfactant (sodium dodecyl sulphonate) with concentration equal to 0.05wt% was added to the prepared nanofluid for increasing its stability. To carry out the micro emulsion phase behavior study, the water-oil ratio was kept to 1; temperature was kept at 80°C and the phase volume measurements were carried for 5 days. The outputs were compared with the emulsion study in presence of only silica nanoparticles and with only surfactant by employing the similar process.
The results show that nanofluid consisting of only silica nanoparticles have a great tendency to form micro emulsion as compared to solutions consisting of only surfactant and nanofluid containing nanoparticles + surfactant for a fixed concentration of 0.05 wt.%. When compared with pure surfactant based micro emulsion study, it was observed that relatively less concentration of silica nanoparticle will be required to form emulsion. The processes and results are outlined and discussed in detailed in the paper.
This study is useful to understand the behavior of silica nanoparticles in forming Pickering emulsion in presence of anionic surfactant and the frontier of using nanoparticle as a potential EOR method before applying to the field scale.
Escola Municipal Pingo de Gente: descobrindo africanidades e redescobrindo identidades
Authors: Villanacci Lidiane Campos , Jauará Manuel 
Published: June 2017

O Programa de Extensão em História e Cultura Afrobrasileira e Africana vem durante a sua trajetória promovendo ações de extensão em escolas do município de São João Del Rei. Refletir sobre a concepção elementar do continente africano prevalecente, desconstruir a visão estereotipada do negro nos livros didático-infantis e resgatar a autoestima das crianças negras em fase de alfabetização em particular na Escola Municipal Pingo de Gente foram umas das ações realizadas no ano de 2014. Através de intervenções de cunho socioeducativos, utilizando de pesquisa participante, o presente trabalho procura apresentar e discutir como o projeto de extensão procurou trabalhar estudos das africanidades e relações étnico-raciais dentro de classes escolares primárias.
Salicylic Acid Effects on Osmoregulation and Seed Yield in Drought‐Stressed Sesame
Authors: Najafabadi Maryam Yousefzadeh , Ehsanzadeh Parviz 
Published: June 2017

Core Ideas
Osmoregulation helps sesame withstand drought.
Diversity exists in sesame genotypes response to drought.
Salicylic acid benefits sesame grain yield.
Drought stress poses a major threat to plant growth, development, and yield. Salicylic acid (SA) is one of the endogenous plant growth regulators that plays a key role in plant resistance against environmental stresses, including drought. A 2‐yr field experiment was performed to assess the modifications in compatible solutes, water status, and seed yield of sesame (Sesamum indicum L.) under drought stress and to see whether foliar application of SA ameliorates these modifications. For this purpose, seven sesame genotypes, namely Yekta, Shiraz, Naz‐Takshakhe, Dashtestan, Isfahan, Varamin, and Oltan, were watered after 60% (control) and 80% (drought) depletion of the available soil water in the presence of two SA concentrations (0 and 0.6 mM). Drought was found to lead to significant reductions in leaf water potential (LWP), relative water content (RWC), seeds/capsule, capsules/plant, seeds/m2, 1000‐seed weight, and, thereby, seed yield and oil content. Significant increases were observed in proline and total soluble carbohydrates (TSC) concentrations in response to drought. Exogenously applied SA alleviated the stress impacts by enhancing all the studied attributes under both moisture conditions, more notably under water deficit conditions. The genotypes exhibited clear differences in their responses to water deficit and SA application. The genotype Yekta showed higher stability in terms of the majority of the studied attributes against drought stress. With the environmental conditions experienced in these 2 yr, osmoregulatory measures were found to serve as indicators of resistance to drought stress while SA seemed effective in the enhancing of these measures in this oilseed crop.