bluuebunny/crossref_metadata_2025 huggingface dataset:
Advances in Reservoir Modeling: A New Approach for Building Robust Reservoir Models
Authors: Kayode B. , Qahtani G. , Thawad F. , Hage A.
Published: June 2017

Due to reservoir description uncertainties, the building of multiple geologic realizations has become an acceptable industry standard for geo-modelling. This paper discusses an approach to rank these multiple realizations, and to determine the geological realization(s) which is/are the closest to reality. It then describes how to further calibrate this best ranked geo-realization(s), especially in situations where there are no production and static pressure data to be used for history matching.

The proposed approach allows us to screen multiple geologic realizations using pressure transient data, and to improve the distribution of permeability away from well control points. The objective is to Rank the several geo-realizations on the basis of global best fit between the simulated pressure transient derivative and the observed pressure transient derivative, then perform a history Match of the pressure derivative for the best geo-model using permeability multipliers, and finally, create a permeability multiplier map, and Spread this permeability multiplier map over the entire best fit geo-model.

Sometimes, the observed pressure transient data may indicate a boundary away from the well, which the original static geo-model may not capture. More so, information from 3D-siesmic may not also indicate any barrier near this well. Using this proposed approach, we can reproduce the well's pressure transient by introducing stratigraphic features in the static model. In the conventional approach, static modeling is solely based on core data measured at well control points, but in this new approach, a dynamic correction factor based on average drainage area permeability is also applied, resulting in a better characterization of the permeability and boundary features.

This approach adds an additional layer of reservoir characterization to geo-modeling by ensuring that the geo-model contains as much dynamic features as possible. In the case of non-producing fields, where there is no further history matching to be done, this new approach guarantees a more reliable static geomodel.
Pushing the Technical Limits in an 8½-in. Section of Manifa ERD Wells Through a Redesigned PDC Bit and Reengineered Drilling Practices
Authors: AlDhafeeri Bader , Alhathelool Mohammed , Salem Loay , Al-Aftan Fahad , Al Mutairi Yousef , Ghazzawi Ayman
Published: June 2017

Over the field development life of the Manifa extended-reach-drilling (ERD) project, extensive drilling tools and practices were introduced to continuously improve drilling performance and well delivery times.

One of the main challenges encountered in Manifa ERD wells lies in landing the 8½-in. section into hard carbonate rocks. Historically, a motorized rotary steerable system (RSS) was used to manage the downhole stick/slip and vibrations experienced by the bottomhole assembly (BHA) while crossing the interbedded hard layers in the 8½-in. section. Engineering efforts were implemented to determine an alternate drilling strategy for the 8½-in. section to overcome such drilling challenges—at lower cost and with a higher performance impact.

Using 4D simulation software, the drill bit was completed remodeled so it could be used on an RSS BHA and still minimize the vibration on drilling tools. This involved revising the cutter count, cutter placement, angle of attack, hydraulics, and gauge configuration. In addition, a thorough drilling parameters road map was modeled to help mitigate downhole vibration. The objective was to constantly remain within the RSS and measurement/logging-while-drilling (MLWD) tool shock limitation to increase their life and ensure reaching the target entry in a single run. Drilling practices were optimized by focusing on improving connections and reaming times without compromising hole cleaning. This performance initiative was implemented in the field in three steps and resulted in unprecedented drilling performance, achieving a record in drilling this long directional 8½-in. section.

As a first step, the redesigned drill bit was introduced in the field to verify the design output in the field and gather the drilling parameters and shock and vibration data with this new design. The design delivered as expected and increased rate of penetration (ROP) by 67% compared with previous records with no shock and vibration recorded on BHA equipment. The second step focused on following the modeled parameters road map from the simulations and improved ROP a further 7%. In the third step of this project, new drilling practices were implemented, which minimized connection and circulation time while maintaining good hole cleaning, tracking of pickup and slackoff weight, and correlating with the torque and drag analysis. The overall drilling performance improved with an increase of 37% in ROP (97.1 ft/hr) over the last record. A total savings of USD 180,000 was achieved on this third attempt, and a new approach to the ERD wells was implemented by the operator's drilling engineering team.

This paper will review the progressive design process and will present the detailed results for each run. Insight will be provided on how this process can be applied to increase ROP performance and reduce cost per foot in a variety of drilling applications.
Critical Micelle Concentration of Different Classes of EOR Surfactants under Representative Field Conditions
Authors: Fuseni Alhasan B. , Al-Zahrani Badr H. , AlSofi Abdulkareem M.
Published: June 2017

The critical micelle concentration (CMC) of surfactants represent the concentration at which surfactant monomers start to form aggregates in order to minimize the energy of the electrostatic and hydrophobic interactions of the system. At this concentration, any additional surfactant molecules are not available at the interface but in aggregates in the bulk of the solution. A measure of CMC for a field surfactant gives an indication of the concentration needed for its effectiveness as an enhanced oil recovery (EOR) agent. This has been shown to be dependent on several factors including the nature of the brine, temperature, and ionic species strength. As such, for field applications, CMCs need to be measured for the particular environment that the surfactant will be used in.

In this work we have measured the CMCs for three types of EOR surfactants. The Du Noüy ring method was used with an automatic dispenser to dilute and measure surface tensions of the various surfactants at different temperatures and in different field brines. The effect of other chemical species, especially polymer was also investigated. Of the three surfactants studied, the betaine surfactant showed the lowest CMC in both injection seawater and field produced brine. It also out-performed the others in temperature stability for all types of brines. The other two surfactants were an amine oxide and an alpha olefin sulfonate. For the field brine conditions, the amine oxide proved to be the poorer performer in terms of CMC while the anionic alpha olefin sulfonate was close to the amphoteric surfactant.

Determination of CMC for real field brine conditions and at elevated temperatures provides a good insight into the performance and potential of different surfactants. Coupled with other tests like phase behavior and interfacial tension (IFT) measurements, very quick decisions can be make about the efficacy of surfactants for field application.
Geophysical Surveillance of a Steam Injection Project in a Kuwait Heavy Oil Field
Authors: Al-Mutairi Amal , Biao Ren Zu , Al-Haqqan Hamad , Tinnin John
Published: June 2017

Kuwait Oil Company conducted a geophysical surveillance program to optimize development options in a shallow heavy oil field in Kuwait. Two optimized 3D Vertical Seismic Profiles (3DVSPs) were acquired in January 2016 to help understand the effectiveness of this EOR project. Goals of this project included acquiring repeatable baseline surveys for 4DVSP surveys, attaining high resolution 3DVSP data, imaging the sealing cap rock shale and two thin vertically stacked reservoirs, and estimating the steam chamber size just after a 30-day steam injection cycle.

One major problem with recording shallow VSP data is the possibility of spatial aliasing due to the slow propagation velocities of P and S waves affecting the ability to achieve desired frequency range. Therefore extensive pre-survey modeling was required in order to determine the optimum source-receiver configuration. The team decided on innovative survey parameters purposely designed to obtain higher frequencies than previously attained in this area to improve the vertical and spatial resolution sufficient to achieve the project goals listed above. The resulting two 3DVSP datasets were then processed and imaged using a patented vector pre-stack Kirchhoff depth migration. Inversion work and qualitative interpretation were then applied to both data volumes to help achieve all the desired goals.

Extensive planning and flawless execution of the two-well 3DVSP operation resulted in the completion of both survey acquisitions in a total of 13 days without incurring any QHSE incidents and having 100% operating efficiency. Frequencies obtained in these surveys were more than 30% higher than previously achieved in this same area. These high frequencies resulted in vertical resolution sufficient to image the sealing shale layer and both of the steam injected reservoir sands as well as the necessary spatial resolution to image a small steam chamber. The novel modelling, acquisition and processing/interpretation methodology described have demonstrated that accurate subsurface imaging in this environment is achievable. The results have contributed to and altered the steam flood expectations and will provide key information that would not otherwise have been available to develop the best development options. Additional 3D and 4DVSPs are currently being acquired.

Extensive modeling enabled innovative customization of an innovative acquisition design, optimized acquisition operations, parallel processing, and interpretation techniques have allowed for a time efficient acquisition-to-results turnaround.
Applicability of Using Electrical Downhole Heaters in Sudanese Oilfields, Modeling Supported
Authors: Elgadi Mussab , Mahgoub Musab
Published: June 2017

Heavy and waxy crudes reduce production, lifting performance and may cause production loss. The common way to solve this problem in Sudanese oilfields is through using Cyclic Steam Stimulation(CSS) technology, however this method has limitations, which made the proper solution is to use Electrical Downhole Heaters (EDH). Unfortunately no body studied EDH application in Sudanese oilfields. This project shows the possibility of using EDH technology in Sudanese oilfields with waxy crudes.

A comprehensive study for literature review for this technology and the types of EDH in terms of components and installation were done. Also number of companies with expertise in this area have been reviewed, with subjective analysis to their case studies. A computational model was developed by using Microsoft excel sheet associated with sensitivity analysis to find major parameters that have a large impact on results. Based on the modelling number of Sudanese fields and wells have been selected to study the possibility of applying this technology to them, by comparing the case studies for wells where this technology was successfully carried out, with some selected wells. A comparison between EDH and CSS in term of process and cost was done.

Simplified model was developed; in order to predict heating cable performance and energy required to heat a well. It was found that (API gravity, pour point, viscosity, downhole temperature and depth) are the major parameters affecting heating performance; by applying the sensitivity analysis. According to our screening and design, we found that the selected wells will give even better performance than ones listed in the literature. It is highly recommended to apply this technology in fields like (Fulla central, Moga, Bambo, Rawat, Hilba, Azrag). finally the economic evaluation illustrates that the cost of using EDH is three times less than using CSS.

This project is not only have huge impact in the oil industry in Sudan, but also shows that there are remarkably high economical value for using EDH.
How Geomechanical Study Helped Minimize Drilling Challenges in Highly Deviated Wells, Offshore, Saudi Arabia: A Case Study
Authors: Ahmed Mujahed , Al-Dossary Khalid S , Baim Ahmad S , Al-Hamad Nasser A
Published: June 2017

A geomechanical study was conducted for one of the drilling platforms in offshore Saudi Arabia, where several highly deviated (well inclination > 80°) development wells were planned. The main objective was to provide safe mud weight ranges and predict possible problematic depths to minimize drilling challenges like pack-off, stuck-pipe, lost in hole, over-pulls etc., which are likely due to wellbore instability. The scope of this work was restricted to the curve section of the planned wells because most of the problematic formations, comprising mainly shale and weak interbedded sand formations, are encountered in the curve section.

The operator's drilling department sought a clear understanding of the geomechanical aspects of these problematic formations to optimize the drilling plan and minimize nonproductive time. A 1D mechanical earth model (MEM) was constructed using openhole log data available from the only exploratory well drilled on this platform. The 1D MEM was further used in conducting post-drilling analyses to validate and history match events related to wellbore instability (like tight spots, pack-off etc.,) that were observed while drilling and stress-related wellbore failure as shown by the calipers.

The developed model was used for analyzing planned well trajectories and providing mud weight window limits to safely drill the highly deviated planned wells. Sensitivity analysis was performed to identify the well inclination limits to drill across the problematic zones whilst minimizing issues related to wellbore instability. The developed geomechanical model was validated using the log data acquired during drilling each of these inclined wells; the predictions from the model were in close agreement with actual observations during drilling.

The outcome of this study helped optimize the well design for upcoming wells in this field. Using the recommendations provided from this study, several highly deviated development wells were successfully drilled and completed. Apart from standard failure analysis, ‘depth of failure’ approach was also taken into account to provide recommendations on optimum drilling mud weight. Utilizing the geomechanical study, extended reach curve sections as long as 5000-ft measured depth (MD) were planned and drilled successfully without any significant nonproductive time (NPT).
A Reliable Method for Determining Fast Shear Azimuth of Sonic Data
Authors: Hamid Osman , Ahmed Omair , Hussain Aborshaid , Ba-Wazir Omar
Published: June 2017

Quantifying anisotropic rock properties from sonic data is a well-known approach that has many applications. For instance, the percentage sonic anisotropy in the formation provides vital knowledge when constructing Geomechanics mechanical models and when determining optimum well trajectory for horizontal wells. One of the main outputs from sonic anisotropy processing is the fast shear-wave polarization azimuth (FSA) derived from auxiliary tool orientation measurements included in the tool string with the sonic tools. This FSA is polarized along the direction of fracture strike, in case of fracture-induced anisotropic zones, and /or along maximum horizontal stress, in case of stress-induced anisotropic zones.

When the hole shape is oval in one axis by breakouts and in gauge in the other axis, the sonic tool remains oriented in one direction throughout logging intervals. As a result, the fast shear azimuth will be stable in one direction. This locked direction inherently has a 90° ambiguity if interpreted wrongly particularly if no borehole image data were available to validate this direction from the strike fractures or breakout directions.

The main objective of the study in this paper is to validate the direction of FSA, and then horizontal stress orientations, from sonic data in vertical wells when the sonic tool keeps a singular orientation throughout the logging and no borehole image data are available to support the direction of horizontal stress orientations. This validation is represented through a graphical interpretation of the FSA, both qualitatively and quantitatively, at intervals that exhibit stress-induced anisotropy and without assist from borehole image interpretations.

Three examples are presented in this paper. The first one shows a determining of the maximum horizontal stress from the graphical interpretation of FSA after processing the sonic data. This interpretation is validated with image data. The other two examples are from wells where only sonic data is used to determine the horizontal stress orientations using the FSA graphical technique
NanoSurfactant for EOR in Carbonate Reservoirs
Authors: Abdel-Fattah Amr I. , Mashat Afnan , Alaskar Mohammad , Gizzatov Ayrat
Published: June 2017

A new class of surfactants for enhanced oil recovery (EOR) applications has been developed in the form of petroleum sulfonate salt nanoparticle dispersions in seawater. These NanoSuractants (NS) are 10- to 60-nm particles of the seawater-insoluble petroleum sulfonate salts, one of the most abundant and inexpensive industrial surfactants, that are resiliently stable in seawater at elevated temperatures via a special class of co-surfactants. They can be easily prepared in the field by mixing with seawater at ambient temperature and injected into the reservoir with seawater without any additional infrastructure. The colloidal nature and extremely small size of the NanoSurfactans particles allow them to migrate and deliver petroleum sulfonates to remaining and residual oil deep in the reservoir without the need of large quantities in order to compensate for losses by adsorption onto the rock surfaces and diffusion into water-filled small pores. This paper reports on the results of few tests conducted to evaluate the performance of NanoSurfactant formulations under reservoir conditions. Results showed consistent colloidal and chemical stability of the NanoSurfactant formulations for over six months at 100°C. They reduced the seawater-crude oil interfacial tension (IFT) by two to three orders of magnitude or formed oil-in-water emulsions at 100 °C without any mechanical mixing. Transmission electron miscroscopy (TEM) images revealed mostly round particle in the submicron range (10- to 60-nm). Finally, core-flood test at reservoir conditions using bottom-hole live oil samples indicated an additional oil recovery of about 7% of OOIP beyond several pore-volumes flooding with seawater by injecting 0.4 pore-volume of the NanoSurfactant at 0.2 wt% concentration.
A Low Elastic-microsphere/surfactant/polymer Combined Displacing Method after Polymer Flooding
Authors: Yang Hongbin , Kang Wanli , Yin Xia , Tang Xuechen
Published: June 2017

Polymer flooding has been widely applied in China and can enhance oil recovery by more than 10%. However, there is about 50% remaining oil in reservoirs. Therefore, it is important to develop a new technology which based on the mechanism of both lowering interfacial tension to an ultra-low value (103 mN/m grade) and improving sweep efficiency of displacing fluid after polymer flooding in extremely heterogeneous reservoirs. A novel dispersed viscoelastic microsphere flooding system (DVMFS) by the combination of low elastic microspheres, surfactants and polymers is suggested. Firstly, the suspension stability of the DVMFS was studied using TSI value measured by stability analyzer. The influence of surfactant concentration, polymer concentration and reservoir temperature was conducted. Then, the ability to reduce interfacial tension was measured using interfacial tensionmeter. Furthermore, conformance control ability was evaluated by double tube parallel model. Oil displacement efficiency of the system was obtained through core flooding experiments under a given reservoir condition after polymer-flooding. The results show that the low elastic microspheres with 23.6 Pa used in this paper has great swelling capability at the reservoir condition of Gangxi Oilfield. The deformable microsphere passes throw the pore throat easily because of its low elasticity. The dispersed system has great suspension stability. The lower the temperature and the higher concentration of surfactant and polymer are, the smaller the TSI value and the better the suspension stability are. Besides, the system has an ultra-low oil-water interfacial tension. The results of double tube parallel model and oil displacement experiment indicate that the injection profile was significantly adjusted and the oil recovery efficiency was increased by 21.66% after polymer flooding. This conformance control is a dynamic one because of the combination of low elastic microsphere, surfactant and polymer, which is different from the common gel conformance control technology. The DVMFS displays a promising application to improve oil recovery after polymer flooding for extremely heterogeneous reservoirs.
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

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

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

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

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

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

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

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

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

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.
Formação para manipuladores de alimentos: conhecimento sobre flavonoides e desenvolvimento de preparações para a alimentação escolar
Authors: Fonseca Karina Zanoti , Pamponet Juliana Santana dos Santos , Dos Prazeres Ana Gabriela Matos , De Lima Carlla Larissa Batista , Dos Santos Ivaneide Pereira
Published: June 2017

O presente trabalho objetivou colaborar com o conhecimento de manipuladores de alimentos sobre o tema flavonoides, subsidiando sua oferta na alimentação escolar através da inclusão de novas preparações. Trata-se de um estudo de coorte longitudinal, realizado entre 2013 e 2016 com 160 manipuladores de alimentos de escolas municipais da cidade de Santo Antônio de Jesus-BA. Inquéritos pré capacitação revelaram que apenas 3% tinham conhecimento sobre flavonoides. Realizou-se 4 formações anuais, sendo desenvolvidas novas preparações de forma interativa com dinâmicas de grupo, vídeo aulas e construção de poemas. Após o ciclo de formação, 91% demonstraram entendimento sobre os flavonoides. Infere-se que as formações contribuíram, sobretudo, para a ampliação do conhecimento e conscientização dos manipuladores de alimentos quanto ao consumo de flavonoides e possibilitou a inserção de novas preparações na alimentação escolar.
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.
Nondestructive Determination of Legume Content in Grass‐Legume Pastures
Authors: Baxter Lisa , West Chuck , Brown Philip , Green Paul
Published: June 2017

Core Ideas

Procedures were more successful when forage species were distinct hues of green.

Overall, predictive accuracy of PowerPoint model was best in Old World bluestem–legume pasture.

Only the visual model showed potential in tall wheatgrass–alfalfa pasture.

To better manage forage productivity and quality, it is important to accurately and objectively monitor legume content in grass‐legume pastures. Current nondestructive methods are too subjective or labor intensive. Recent research has led to developments in digital image analysis (DIA) and remote sensing techniques useful in pasture research and management. Four nondestructive sampling techniques were compared with traditional botanical hand separations to determine their ability to predict legume content in pastures of tall wheatgrass [Thinopyrum ponticum (Podp.); TW] and alfalfa (Medicago sativa L.): TW‐alfalfa; and in pastures of Old World bluestem [Bothriochloa bladhii (Retz) S.T. Blake; OWB], alfalfa, and yellow sweetclover (Melilotus officinalis L.; YSC): OWB‐legume. Each sampling procedure better estimated and predicted legume content in OWB‐legume pasture (R2cal = 0.40 to 0.78; R2pred = 0.40 to 0.78) than in TW‐alfalfa (R2cal = 0.02 to 0.61; R2pred = 0.08 to 0.61). Overall, the best predictive accuracy was obtained with the PowerPoint model in OWB‐legume pasture. Only the visual model showed potential in TW‐alfalfa because these two species were difficult to distinguish on‐screen by DIA methods or using spectral thresholds. The use of nondestructive sampling techniques to measure legume content is promising for mixed pastures when the grass and legume components are distinct hues of green. Although the need for more research is recognized, the ultimate goal is to apply these findings to automated scanners that offer producers rapid measurements of legume content in mixed pastures.