bluuebunny/crossref_metadata_2025 huggingface dataset:
Developing Project Management Professionals in QATAR
Authors: Jaidah Bader AL
Published: December 2015

TAFAWOQ, which means "excellence" in Arabic, was established in 2011 as a regional non-profit Project Management Centre of Excellence, to deliver a world-class course program which aims to develop the competencies of project managers for capital projects in the State of Qatar and the GCC.

The Hamad Bin Khalifa University (HBKU), Qatar Petroleum (QP) and Qatar Shell developed the TAFAWOQ initiative in supporting Qatar National Vision 2030 (QNV 2030), one of the most ambitious development programs in the world. This program is accompanied by investment projects valued at more than US$ 230 billion.

A Memorandum of Understanding between the three partners was signed in October 2012.

This paper illustrates how TAFAWOQ contributes to the development of the competencies of project managers and other participants in project teams in Qatar and the region. In summary, this is through:

The delivery of a world-class course program for project managers and those participating in projects in the State of Qatar and in the GCC region. This program is developed in conjunction with the Shell Project Academy, Cranfield University in the UK, Technical University Delft in The Netherlands, Queensland University of Technology in Australia, and the University of Texas in Austin.

Community Events to promote networking and provide the project management community with a forum to discuss major subjects regarding project management in the GCC region.

Tailored courses to address specific requirements of regional companies and delivery of courses at their premises.

Toolbox sessions to refresh what was presented in our courses or to address a particular topic.

Over 250 project professionals from companies in Qatar and other countries in the region successfully completed the TAFAWOQ programs and four community events were organized. Meanwhile, the first batch of course participants passed the APMP examinations.
Updating the Structural Model on a Mature Carbonate Field With Geosteered Wells: Integrating Well Site Knowledge and Tools Through 2D Structural Well Section Models
Authors: Tawilé E. , Gowardhan M. , Baithotty L. , Moreau O. , Pigeaud T. , Bounoua N.
Published: December 2015

Extended Abstract

The field is a Cenomanian carbonate reservoir hosted in the Mishrif formation. Its upper reservoirs are made up of stacked, aggrading parasequences of a Rudist platform system. Some of the best reservoir intervals are just a few meters thick, typically three meters, and represent the main targets for infill well drilling . Given their thicknesses and the seismic resolution, none of the thin reservoir layers can be picked on seismic. Typically, only the Top Mishrif erosion can be picked–with, of course, its set of uncertainties–as well as a bottom bounding surface of the upper reservoirs. However, in accordance to the sequence stratigraphy framework, the reservoir layers are relatively isopach at the field scale and can hence be reconstructed through calibration of the well tops during the landing phase of the well. The wells are designed as very long horizontal drains to be geosteered within these thin reservoir layers. The typical length of the geosteered section in these thin reservoirs is of 2000 m for the shortest and up to 5000 m for the longest ones. These wells bring a lot of information related to the field's structure. Indeed, the use of imagery logs, the crossing of faults or bed boundaries and other structural features enable the structure to be constrained along the well trajectory. Moreover, by adding a few hypotheses to the previous elements, it is possible to generate a 2D structural section of the reservoir along the well trajectory. This is what well site geologists in Qatar do on a daily basis when geosteering the well in no more than three meters thick layers.
Integrating Stochastic Seismic Inversion and Classification Results in the Geological Model: a Feasibility Study on an Offshore Carbonate Reservoir
Authors: Tawilé E. , Pernia L. , Ruelland P. , Piazza J-L.
Published: December 2015

The objective of this paper is to present the feasibility study carried out –in a carbonate field context– on the integration of stochastic inversion and classification results in a geological modeling workflow. Indeed the geological model is based on a seven –log defined and core calibrated– electrofacies scheme while the stochastic seismic inversion and classification provides P and S-Impedances (IP & IS), Poisson's ratio (PR) and lithology probability of occurrence cubes. Making the link between lithologies –limestones and dolostones in our case– and the electro facies scheme is the main topic addressed in this feasibility study.
Stimulated Reservoir Volume 101: SRV in a Nutshell
Authors: Vera F. , Shadravan A.
Published: December 2015

During the evolution of technology to successfully produce shale reservoirs, a term called Stimulated Reservoir Volume (SRV) was introduced. Since then, several authors made efforts to identify, characterize or optimize the stimulated reservoir volume. However, as current literature holds, only a few attempts have been made to summarize and analyze all these contributions. The purpose of this work is to discuss SRV, its different concepts and calculation methodologies to diminish the uncertainty and improve the understanding on unconventional hydrocarbon production.

Several techniques are discussed from literature that calculates different volumes, their names and their time-frame scope of analysis that can go from microseismic observation to stimulation to rate transient analysis to numerical simulation. Differentiation between stimulated volume and producing area is also discussed. A discussion over created fractures and the inherited debate over fracture height and brittleness are investigated. Finally, it is reviewed the changes during and after refracturing of maximum horizontal stress, permeability, conductivity and fracture dimensions and it is impact in SRV.

Based data from several hydraulic fractured wells, our observations suggest an effective improvement in the prediction of permeability distribution if more than one SRV concept is applied analyzed at different time intervals. Also results reflects the fact that micro seismic aids SRV characterization as an effective tool. Another observation for improved production is the importance of mobility for shale gas and shale oil that requires creating fracture complexity for the former to be more productive and planar fracture for the latter.

This work delivers a synopsis of several standpoints about Stimulated Reservoir Volume towards a better identification of optimum lateral length location, orientation and proppant volume. This fundamental review will aid reservoir, completion and stimulation engineers on the understanding of the factors that contribute to successful production from unconventional shale reservoirs.
Well Clean-Up Through Topside Production Facilities
Authors: Rondón González Marianna , Kané Moussa , Passade-Boupat Nicolas , Hurtevent Christian
Published: December 2015

In oil industry economic context, the clean-up of wells through surface production facilities is an option in order to minimize environmental impact, economize rig days and commercialize produced clean-up oil. Clean-up operations through offshore topside production facilities started to be performed some years ago. However, many risks must be considered, especially production chemistry risks linked to compatibility between drilling/completion and production fluids. The goal is to ensure process stability and final quality of oil and produced water which, in many cases, must comply with rigorous specifications for coastal discharge or reinjection into the reservoir.

This study shows the methodology developed to evaluate separation and deposits risks. As a general observation, experiments performed show a degradation of the separation process when drilling/completion fluids (completion brines and CaCO3 particles from drilling muds) are added to the emulsion. The most probable hypothesis is that some solid particles will adsorb at the oil-water interface and affect the stability of emulsions. Nevertheless, additives that change the wettability of solids seem to enhance separation, ensuring a separation efficiency equivalent to the system without particles.

In the case of oils that contain very high molecular weight naphthenic acids (TPA), the use of brines with calcium chloride increases the risk of naphthenic salt deposits at topside facilities. The degradation of the water quality was also observed and the optimization of a reverse demulsifier is then required.

The final clean-up strategy should also be adapted to topside design and possibilities to handle drilling fluids. How to separate and recover debris could be a problem for brown fields. For new projects, some additional provisions may be included in the design for well clean-up. In any case, a multidisciplinary risk evaluation is always required to ensure the good progress of this type of operations.
Screening of Polymers for EOR in High Temperature, High Salinity and Carbonate Reservoir Conditions
Authors: Quadri Syed Mohamid Raza , Shoaib Mohammad , AlSumaiti Ali M. , Alhassan Saeed M.
Published: December 2015

Polymer flooding is one of the most attractive chemical EOR techniques for sandstone reservoirs however due to complex geological heterogeneity and harsh reservoir conditions its full potential has not been explored in carbonate reservoirs. The main reason behind this limitation is the inability of conventional EOR polymers like HPAM and Xanthan to withstand these conditions. Candidate polymers must provide the required rheology at minimal polymer concentration, be thermally and mechanically stable, and result in a manageable adsorption on the reservoir formation. A polymer screening study has been conducted on a series of polymers, to identify the most suitable candidate that can tolerate the harsh reservoir conditions. Initially, rheological measurements are conducted on a series of polymers followed by filterability, injectivity, static and dynamic adsorption, mechanical and thermal stability testing as a screening criterion for polymers in EOR operations. Amongst the tested polymers polyacrylamide based co- and ter-polymers showed reasonable temperature stability with low salinity tolerance. Whereas, biopolymer Schizophyllan a polysaccharide showed shear thinning behavior with positive thermal stability and salt tolerance. Long-term thermal stability of biopolymer is also conducted at a temperature of 120 °C and salinity up to 220 g/L under anaerobic conditions for over eight months and no viscosity loss is observed. Biopolymer showed acceptable injectivity on cores of permeability more than 30 mD. Core flood effluents viscosity reached 40% compared to injected sample. In addition the mechanical stability and filterability of biopolymer are also discussed.

Static as well as dynamic adsorptions of biopolymer have also been studied. The static adsorption on four natural minerals (Calcite, Dolomite, Kaolin, and Silica) as well as formation rocks is reported. Out of these four minerals, maximum and minimum adsorption is observed on Dolomite and Kaolin respectively. The adsorption of biopolymer decreases with salinity and temperature. Adsorption on carbonate reservoir rocks is found to be low when compared to pure calcite and dolomite minerals. Dynamic adsorption on cores with different permeabilites (3 to 165 mD) is measured to be low in magnitude (47.5 to 0.53 µg/g).
Embedded Response Surfaces Approach for Uncertainty Quantification
Authors: Busby D. , Chugunova T.
Published: December 2015

Uncertainty quantification on reserves estimation is a fundamental task for project validation on offshore green fields and also for the selection of a development plan that is robust to those uncertainties. To test the robustness of several development plans is then fundamental to be able to evaluate the impact of this uncertainty with low computational cost.

Structural, geological and dynamic uncertainties are integrated in a new workflow based on a set of embedded response surfaces. The first step consists in building an experimental design with only structural and geological parameters to evaluate the impact of such uncertainties on static responses such as oil initially in place. In the second step, this experimental design is completed with additional dynamic parameters. The novelty of the static and dynamic design merging is to incorporate the previously obtained static response surface in addition to the uncertain parameters. By embedding the static response in the variables we obtain a response surface on the reserves more regular and more predictive. In this workflow, mainly applied to green fields, the impact of local geological uncertainty is usually of second order respect to other global uncertainties and it is taken into account as random noise whose variance may depend on the static response.

The method is applied to a real green field with complex multi-level heterogeneities and it is compared to more standard approaches such as Monte Carlo. We manage to obtain a very good response surface quality for the static response (oil in place) that is then embedded in the reserves response surface.

The final accuracy of this response surface is sensibly increased respect to a classical approach considering only static and/or dynamic parameters at minor costs in terms of reservoir simulations.

The new approach reduces sensibly the number of reservoir simulations needed for an accurate uncertainty and risk assessment when applied to select the more robust development plan selected from a set of possible candidates. It also provides useful sensitivity analysis measures to guide possible data acquisition campaign in order to reduce risks and take better decisions.
Karst Paleogeomorphology Reconstruction of Early Ordovician Carbonate Unconformity and its Petroleum Significance, Tazhong Area, Tarim Basin, West China
Authors: Tong Yanming , Zhang Zhenghong , Hauser Ken , Xie En , Yang Pin , Wang Peng
Published: December 2015

Karst carbonate reservoir is playing more and more important role in current petroleum industry, and it is the same in study Tazhong area of middle Tarim basin and even the whole basin. Meanwhile, it is noted that paleogeomorphology of carbonate karst unconformity has obvious control on reservoir development and even hydrocarbon accumulation based on many case studies. Therefore, paleogeomorphology reconstruction is often very fundamental but indispensable study for exploration and production activities in such kind of reservoirs.

The study carbonate unconformity, i.e. the top of Yingshan formation of early Ordovician, typically occurs at burial depth of 5.2~6.5 km, which is almost the same as that of northern Tarim basin, such as Lungu area. However, there are more challenges here in the work of paleogeomorphology reconstruction for Tazhong area when compared to that for northern Tarim basin: 1) the study carbonate unconformity has much lower relief contrast on paleogeomorphologic micro-unit scale, 2) the overlying formation of Lianglitage is carbonate-dominated and contains many reef-shoal intervals (especially for the upper Lianglitage formation), and 3) the current structure of unconformity horizon seems much different from paleogeomorphology surface. These cause that the often-used methods fail, for example, the paleogeomorphology derived from the whole thickness of overlying Lianglitage formation will be distorted because of higher carbonate production rate at some topographic highs, which is different from a normal clastics case where thicker usually means lower and thinner means higher, like the situation in northern Tarim basin.
Expression of the Zagros Orogenic Event in Qatar
Authors: Wright C. E.
Published: December 2015

Expression of the Zagros Orogenic Event in Qatar

The objective of this paper is to demonstrate the effect of the orogenic events leading up to the main Zagros Orogeny on the stratigraphic succession in Qatar.

The full extent of the erosional event was not appreciated by earlier stratigraphers in the region which lead to a plethora of names and a complicated and confused association of stratigraphic relationships. Detailed correlation of well log suites from more current wells across onshore and offshore Qatar has allowed the development of a stratigraphic framework that embodies the work of many earlier stratigraphers and explains some of the challenges faced by them.

In Qatar the Coniacian rocks above and the upper Cretaceous rocks below the Late Cenomanian to Cenomanian/Turonian unconformity record the onset and history of the Alpine orogenic events in this region. These events are the start of the collision between the Arabian and Iranian plates and are what we know as the Zagros Orogeny. The Cenomanian/Turonian unconformity represents an hiatus of roughly 9 million years during which over 1,100' of section was removed along the axis of the Qatar Arch. Maximum erosion occurred on the crest of the arch close to the present day Qatari/Iranian border.

The stratigraphic scheme is quite simple. Pre-collision tectonic events which heralded the onset of the impending major orogenic event produced unique erosional events within the Mishrif Formation. Erosional wedges within the Mishrif Formation were the result of reactivated structures associated with the Qatar Arch. The application of this new understanding to drilling and seismic interpretation allows us to better understand drilling risks and complex velocity profiles.
Investigating the Role of Ultrasonic Wave Technology as an Asphaltene Flocculation Inhibitor, an Experimental Study
Authors: Amani Mahmood , Retnanto Albertus , AlJuhani Salem , Al-Jubouri Mohammed , Shehada Salem , Yrac Rommel
Published: December 2015

Asphaltenes deposition is one of the common problems encountered in the petroleum industry as it clogs the area near the wellbore, builds up in the well tubing, and precipitates inside separators and other surface facilities. Thus, it restricts the flow of the fluids from the formation to the wellbore and to the surface and, hence, leads to production loss. The remedial measures for asphaltenes deposition, however, cost money and time.

The aim of the study presented in this paper was to experimentally investigate the role of ultrasonic wave technology as an asphaltenes flocculation inhibitor and to quantify the actual reduction in asphaltenes content of the crude oil when ultrasonic waves were applied. For these purposes, sonication experiments, viscosity measurements, and asphaltenes extraction experiments were performed. Moreover, this study aimed to verify the results and the conclusions that were achieved in a previous similar work by repeating some of the methods they used with different crude oil sample.

Conducting this experimental study led to the conclusions that ultrasonic waves have the ability to break down asphaltenes conglomerates and, hence, reduce asphaltenes content in crude oil samples and that there is an optimum time for sonication at which highest asphaltenes particles disintegration is achieved. Moreover, it was concluded that the crude oil viscosity is influenced by its asphaltenes content.
Correlative XRM and FIB-SEM for (Non)Organic Pore Network Modeling in Woodford Shale Rock Matrix
Authors: Goral Jan , Miskovic Ilija , Gelb Jeff , Andrew Matthew
Published: December 2015

Typical shales are characterized by their small pores and their very low porosity and permeability, hence making these rocks challenging in obtaining economically viable gas and/or oil. A considerable amount of effort has gone into measuring and characterizing the pore volume both within organic matter and mineral shale rock matrix, and investigating which pores really contribute to these petroleum systems. Therefore, quantifying the amount, size distribution and connectivity of pores within shale reservoirs is at the heart of both production and storage issues.

A new holistic approach for characterization of nanoscopic scale structural heterogeneity in shale, presented here, couples micro and nano X-ray microscopy (micro- and nano-XRM) with focused ion beam scanning electron microscopy (FIB-SEM). This integrated approach provides a unique opportunity to characterize in great detail the complex three-dimensional (3D) microstructure of shale over multiple length scales, from the centimeter length scale to the single nanometers. To explore the practical significance and reach of this newly developed analytical framework, a shale specimen from the Woodford formation was imaged several times with non-destructive XRM at successively higher resolutions, and then finally imaged with the ultra-high-resolution by destructive FIB-SEM serial sectioning. Further to the imaging, the organic- and nonorganic-matter-related pore networks within Woodford Shale matrix were extracted using the FIB-SEM images, in order to quantify the evolution of porosity associated with both organic and nonorganic matter.

The findings indicated that the organic-matter-related pore network strongly dominates over the nonorganic-matter-related pore network within the investigated specimen, suggesting a strong relationship between porosity and organic content.
Challenges and Opportunities of Modelling Long Horizontal Wells. A Case History
Authors: Arata F. , Cardola P. , Costanzo C. , Grilli F. , Valdisturlo A. , Burt J. , Chinellato F. , Denichou J.
Published: December 2015

Nikaitchuq is an oil field on the North Slope of Alaska that has been developed with more than 60 extended-reach wells having 6,000-ft to 18,000-ft-long horizontal sections. The main reservoir interval in Nikaitchuq corresponds to a shelfal lobe composed of two main sand bodies, encased in structural depressions. The development scheme consists of waterflood line drive with horizontal producers and water injection wells located side by side. The majority of the development wells were designed with a single horizontal trajectory undulating between the two main sands bodies in counter phase with the related water injectors.

To be successful, such challenging well design requires accurate geological modeling, effective geosteering capabilities, and sensible well data acquisition. The objective of the approach here described is to correctly reconstruct the reservoir geometry by integrating numerous data and information coming from such long horizontal wells. However, data and information that have originated from different sources have different levels of accuracy. A thorough data quality assessment is a mandatory step in any data integration exercise. Hence, all information available in each horizontalwell section was reviewed in detail and cross-examined. Bed boundary mapping data interpretation via different inversion processes and log and image interpretations (such as gamma ray, neutron density, resistivity, density images, deep azimuthal electromagnetic data) were compared, validated, and integrated in the 3D geological model to perform a very precise reconstruction of reservoir internal geometry.

Such accuracy in modeling was not only aimed at enhancing the precision of volumes in place and resource estimates, but it was also a prerequisite for the successful drilling of the subsequent wells during the field development.

The novelty of the approach consisted in the integration of density image logs, bed boundary mapping data, and resistivity modeling results to derive accurate information on the reservoir geometry at a scale useful for 3D modeling. This use of data goes beyond common practices.
Innovative Application of Ultra-Lightweight Epoxy Resin-Cement Slurry Mixture Achieved Zonal Isolation Objectives and Secured Well Integrity: Case History From Offshore Gulf of Suez
Authors: Bhaisora Devesh , Aly Ahmed , Morsy Ahmed , Shamma Hesham , El Nashar Radi , El-Sayed Abdel Karim Salah Eldin
Published: December 2015

While drilling an offshore well in the Gulf of Suez (GoS), Egypt, an operator experienced severe losses of approximately 14,500 bbl of costly oil-based mud (OBM) during the drilling of a 12 1/4-in. hole section through depleted zones. It became obvious that zonal isolation objectives would not be achieved unless equivalent circulating density (ECD) was significantly reduced during cementing to help minimize and control downhole losses.

Therefore, a special design of ultralightweight cement slurry combined with epoxy resin was prepared. The goal was to help reduce downhole losses during cementing while enhancing mechanical properties and achieving higher compressive strength of the set cement sheath as per well integrity requirements. This would help prevent formation stress and be helpful during future well construction operations. Epoxy resins are primarily used as secondary barriers to the primary cement sheath, curing tight casing leaks, squeezes, and during well abandonment. Generally literature on resin discusses its resilient mechanical properties, highlighting that the Poisson's ratio of epoxy resin can be closer to that of rubber, while cement is closer to that of glass.

It was observed that mixing resin with cement enhances other mechanical properties of cement in addition to enhancing compressive strength. A 9-lbm/gal resin-cement slurry mixture was designed for the discussed treatment, combining 90% cement and 10% epoxy resin. The combined mixture provided all of the necessary properties of the desired cement slurry. The cement treatment was performed as designed and met all zonal isolation objectives.

This cement-resin mixture can become a new solution within the industry, replacing conventional cement in many crucial primary cementing applications, particularly replacing ultralightweight high-compressive-strength slurries. This paper highlights the necessary laboratory testing, field execution procedures, and treatment evaluation methods so that this technology can be a key resource for such operations in the future.
An Innovative Approach for Tubing Integrity Monitoring With the Application of Electromagnetic Tool and Caliper Tool in Tandem
Authors: Norintan Farina Haziq , Hafiz Azzad , Safwan Aliff , Norfasya Norfasya , Xiong Choi Yee , Zawawi Ahmad , Yusmanizeil M. , Aisyah Siti , Idham M. , Wahyudeen M.
Published: December 2015

Caliper survey is well known for its accurate measurement of inner casing and tubing since the introduction to the market few years ago. From the survey, most pipe integrity issues with failure size as small as pitting can be measured to a better understanding on the tubing conditions. Most of the failures on pipe developed over time and small pitting more than often turn into damaging large hole as time goes by. Thus, caliper survey provides an ideal solution for monitoring the pipe integrity condition.

Not until the recent innovation of a new electromagnetic tool altered the perspective on monitoring the pipe integrity condition. By combining with caliper tool, it improves the pipe integrity survey by identifying the location of weaknesses; in specific the exact point of metal loss, as well as to measure the thickness of the tubing. Applying the remote eddy current concept, the magnetic wave will travel from the wave generator, along the outside of the casing before passing back through the 12 sensors mounted on the inside of the tool's bowsprings. The casing thickness affects the arrival time, phase and amplitude of the returning signal and this info will be analyzed with the improved 3D visualization software and statistical software.

Three (3) wells; A, B and C were completed during 1990's. The wells have high CO2 content at 9–15%. Surface facilities in the field have limitation in handling high CO2 fluid, thus these wells were producing intermittently from 1996–2010. An upgrading of surface facilities were undertook from year 2012–2014 to maximize the technical potential of the wells in the field. Workover job was agreed upon the upgrading but intervention team has another idea in looking into the matters. A logging survey was proposed consists of caliper, electromagnetic and pressure gauge to evaluate the conditions of the tubing integrity. The logging involved the entire tool associated in real time and tandem, the first time ever done in this region. The results from the survey showed differences of corrosion percentage between caliper data only and combination of caliper and electromagnetic tool. Combining these techniques of survey in tandem gives a more details corrosions percentage and thickness compared to caliper only. It also minimized the operation logging time and well downtime. In conclusion, it was found that the current tubing thicknesses of these wells are within the allowable corrosions rate, consequently workover campaign was dropped and roughly around USD 30 Million had been saved.

The comprehensive strategy on running these surveys in tandem provided in this paper can be used as guidance for an innovative approach in corrosion monitoring.
Pilot Trial of HR-PCP Technology for Heavy Oil Reservoir in KOC
Authors: Mali Prasanna Vasant , Al-Jasmi Ahmad , Saleh Iskander , Al-Ajeel Fatemah , Mariam Zerai , Shah Jignesh , Al-Olaimy Saber
Published: December 2015

Exploitation of heavy oil fields is a challenging task in Kuwait Oil Company (KOC). Most of these fields require artificial lift to produce optimally. Reliability, operational ease, run-life and steady oil gain, are the key issues, for application of artificial lift, to produce heavy oil. It is our constant endeavor to seek value addition, with regard to these parameters. In view of this, pilot of ‘Hydraulically Regulated PCP’ (HR-PCP) technology, is implemented for heavy oil cold production.

Preliminary studies revealed that HR-PCP technology is designed to handle multi-phase flow conditions more efficiently, due to its unique design. Pilot trial is carried out for a representative heavy oil reservoir, having crude oil gravity of 14°API, with top of the perforation at 7819 feet. Objective of the pilot is to evaluate performance of HR-PCP technology, with regard to the heavy oil cold production. Study is based on actual field implementation and does not include any lab studies.

The paper, essentially, encompasses various aspects of the pilot such as pilot methodology, technology evaluation, candidate well selection and HR-PCP design as well as details regarding pilot implementation and pilot study results. During the pilot period, relevant pump and well parameters are constantly monitored, with an aim to optimize pump performance.

It is concluded from the pilot results that implementation of HR-PCP technology, for this heavy oil reservoir, is proven to be successful in terms of achieving steady oil gain and sustained run-life. Maximum oil rate of 567 b/d and peak MTBR of over 400 days, are achieved during the pilot period. Pilot studies have also prompted us to install HR-PCP technology for other similar wells.

Thus, HR-PCP technology emerges, as a viable artificial lift mode for our heavy oil production strategic plan. Results amply demonstrate that the technology can also be applied for other heavy oil reservoirs of similar nature.
A Study of the Applicability of Bourgoyne & Young ROP Model and Fitting Reliability through Regression
Authors: Kutas D. T. , Nascimento A. , Elmgerbi A. M. , Roohi A. , Prohaska M. , Thonhauser G. , Mathias M. H.
Published: December 2015

Pre-salt layers has long-term exploration and production possibilities, however the properties of such layers are highly challenging for exploration (i.e. these carbonate layers are highly abrasive, located deeper than 5000 m, have generally low permeability) and production (i.e. pre-salt layers are located in harsh oceanic conditions, hundreds of km offshore). These conditions mean increased exploration technological and economic difficulties. One of the partial solutions to decrease costs is to reduce the drilling operations time. Rate of penetration (ROP) has a significant effect on the overall drilling time, driving ROP modeling and optimization to be a viable solution for reducing drilling operations time in such environment. Several mathematical ROP models were developed in the last five decades in the petroleum industry, departing from rather simple but less reliable R-W-N (drilling-rate, weight-on-bit and rotary-speed) equations until the arrival to a comprehensive and complex approach: Bourgoyne and Young ROP Model (BYM) which was first published in 1974.

The paper explains the equation, how it is applied in terms of ROP modeling, identifies the main drilling parameters driving each sub-functions, and introduces how they were developed. The paper base itself on the sub-functions of the equation, explains the normalization factors which have significant influence on the model, and also introduces simulations which aim to understand the approach by applying the equation in a pre-salt layer case study. Knowing that, the original publication was introduced in 1974, this paper also aims to identify rooms for improvement and/or alternate the sub-functions to match actual field data better than with the originally given drillability coefficient recommended boundaries stated in the first publication. This is accomplished through a real-world practical application of this ROP model in a pre-salt layer. The paper also assesses the limitation in terms of the applicability of this complex model for ROP analysis and optimization in such carbonate layers.
Managing an Effective Centralized Control Room for Brown Field Projects in Gas Plant
Authors: Dey Nilangshu
Published: December 2015

Natural Gas liquid (NGL) Plants in Qatar have undergone major operational transformation during the last decade. The large step change in operational strategy and efficiency has occurred due to automation evolution taken place in monitoring, control and protection technology of all Gas plants of Qatar Petroleum.

The Paper will focus how the major upgrades of the Plant control and safety systems done thru various brown field projects which have introduced new centralized operational interfaces resulting multiple operating systems in the same control room and ultimately the final solution done in integrating all such operating systems to an ergonomic control room environment.

It highlights the various challenges faced while implementing such brown field projects at different stages within the existing control room environment. Few of such upgrade projects has also been highlighted which has created direct impact on operations in achieving various benefits.

Further the Paper highlights detail case studies on NGL-3 Plant where such brown field projects has made operational hindrance and subsequently major revamping projects were undertaken to integrate the various control systems into a single operating platform with ergonomic operators console and control room layout for 24 X 7 effective operation.

The Paper also provides the multifold operational benefits of rationalization of centralized control room environment thru integration of multiple satellite control systems and converting the operator interfaces to ergonomically designed Extended Operator Console for 24 X 7 efficient operation. It provides the various elements which has directly contributed towards the real operational benefits.
Structural Uncertainty and Inverse Characterization of Discrete Fracture Networks with Dynamic Data
Authors: Vargas-Murillo B. , Vargas-Guzmán J. A.
Published: December 2015

The realism of modeling well stimulation by hydraulic fracturing, in 3D reservoir grids, heavily depends on the match between the predicted multiple-scale discrete-fracture-network (DFN) and its flow properties, versus the monitored fractures at drilled rocks. Unfortunately, monitoring the hydraulic fracturing phenomena and connectivity of DFNs at multiple scales is highly uncertain. Although fracture orientation and location are measurable at wellbores, and microseismic has contributed to characterize hydraulic fracture geometry; the subseismic connectivity of hydraulic and natural fractures with sweet-spot rock-bodies at larger distances demands advanced integration of preexisting structural features into numerical models. Therefore, modern fracture optimization demands the use of 3D stochastic reservoir models. Additionally, mismatches between the reality and the model are incidentally observed by comparing bottomhole pressure and multiphase flowrate response in flow models versus downhole monitored data. Attempting to recreate the fracturing process requires coupling hydraulic injection, fracturing geomechanics, proppant transport, and flow under preexisting structural uncertainty; at multiple scales. Although tools for modeling such a complex workflow exist, results do not automatically match microseismic or other advanced observations, due to preexisting structural uncertainty in the model, and/or limitations of the tools themselves.

In this paper, the importance of multiple-scale structural-heterogeneity is emphasized, and the use of "practical" inverse problem solutions of DFN models is suggested for its characterization. The proposed inverse approach is to modify structural object positions, attitudes, and geometries, instead of upscaled flow properties. An industrial scale example of such approach, where the size of pseudo-compartments is controlled by subseismic sealing faults, is recalled. Errors in pressure response are correlated to fracture displacements along normal vectors. The use of streamline simulation to facilitate tomography of DFN intensity is evoked. The multistage fracking process is also proposed to be handled with the same approach, modifying the geomechanical fracture model to match monitored flow and proppant transport response. Finally, novelties for monitoring proppant transport during fracturing are also highlighted.
Design, Installation and Integrity Management Challenges of Bolted Connections for Offshore Brownfield Modification Projects
Authors: Nezamian A. , Iqbal K. , Nicolson R.
Published: December 2015

The integrity management, changes, repairs, upgrades and modification of offshore infrastructure to meet the functionality and operational availability requirements presents a constant and growing challenge for operators. A bolted connection arrangement can form a constructible and cost effective solution for the modification of existing platforms with minimum impact on platform operations. Historically, bolted connections have been avoided due to concerns about integrity management and degradation mechanism uncertainties and corrosion in particular. However, where structures are not in direct contact with sea spray, and given appropriate safety and integrity procedures, bolted connections can be used successfully on live production platforms to mitigate risks without the exposure to hot work.

The use of bolted connections covers a wide range of applications. This implies that the requirements for a bolted connection must be specified in relation to the given application and its criticality. As the requirements for fastener material, specification/design and installation are defined based on the given application, the present guideline does not provide specific requirements (minimum requirements) that can be used universally. In addition the installation procedure assurance, integrity management and corrosion protection of bolted connections require an appropriate degree of attention.

This paper gives an overview of the challenges and discusses various aspects of bolted connections related to brownfield modification of offshore structures. The discussion aims to represent potential risks to the integrity and the required mitigation actions and overall requirements for design, installation, maintenance, re assessment and repair to maintain the structural integrity of the bolted connection and attached structures. The paper also provides an overall view on the documentation and calibration/validation of the bolted connections required to ensure an adequate safety level is maintained by means of maintenance and inspection programs.
Designing of Successful Immiscible Water Alternating Gas (IWAG) Coreflood Experiment
Authors: Khanifar Ahmad , Raub Mohd Razib Abd , Tewari Raj Deo , Zain Zahidah M , Sedaralit M Faizal
Published: December 2015

Average recovery factor in offshore field under discussion is relatively moderate due to wider well spacing and poor sweeping efficiency thus leaving significant volume of oil behind in the reservoir. Timely application of EOR is therefore necessary to enhance the recovery factor to a reasonable level. Among the various EOR processes and techniques of EOR screened, studies found immiscible water-alternating gas (IWAG) injection as the most suitable and viable option for this Malaysian mature offshore oilfield. Realistic estimate of incremental oil by EOR is paramount as IWAG application involves high CAPEX and OPEX project. Therefore, representative is required to be generated in the laboratory for constructing a realistic reservoir simulation model to understand the three phase flow in porous media and support the IWAG process for full field implementation. Important parameters in this case are residual oil saturations in sequential injection of displacing fluids water and gas and trapping of gas, injection volumes and frequency of alteration. Therefore, IWAG core flooding experiments under reservoir conditions need to be performed, results quantified and parameters for hysteresis modeling established.

This paper addresses the challenges and strategies of IWAG core flooding experiment performed under reservoir conditions using representative composite native cores, live reservoir oil sample, field produced gas sample and synthetic formation brine water. The laboratory injection rates are considered equivalent to the field fluid advance velocity like in any standard displacement steps. Also, gravity stable injection mode is considered to achieve the best IWAG displacement performance. These challenges and strategies are drawn from lessons learned during accomplishment from earlier IWAG core flooding experiments. The IWAG core flooding experiments were performed on composite field core samples, arranged according to Langaas method, using current field production gas with 60 mole % CO2. The composite reservoir core samples were initially saturated with live oil and irreducible formation water and then flooded with formation water and seawater to residual oil saturation at reservoir conditions. Following, waterflooding, a number of water and gas cycle slugs were injected. The displacements were conducted at pressures well below the estimated minimum miscibility pressure during these experiments. Laboratory studies and numerical simulation study conducted on the applicability of immiscible WAG injection using high CO2 content produced gas indicated that 7.0 % additional oil recovery over waterflooding period can be recovered.
Improving Brownfield Project Performance
Authors: Visser Folkert , Burger Mark , Laws Simon
Published: December 2015

Brownfield project performance

When a new facility starts up, a new brownfield site is created. Through technology improvements we are able to get more production out of our existing assets and getting access to new frontiers is increasingly complex. These factors raise the importance of doing brownfield projects well.

But, the schedule and cost slippage that is often found in capital projects is significantly worse for brownfield projects.

Typical issues in brownfield projects

Project cost growth and schedule slippage often occurs in the early phases of the development. Project and asset teams may lock themselves into pre-determined solutions for brownfield projects without spending sufficient time on the front end loading, driven by an attitude of already knowing what needs to get done. Surprises appear during execution because of a lack of understanding of the facilities, such as its current condition, the process constraints and the restrictions to execute the projected work. Estimates and schedules can grow because they were based on analogues or factors, which turn out to be unreliable due to the unique nature of each brownfield project.

Best practices

Due to their many interfaces and complexity, brownfield projects require discipline: to spend time to truly understand the asset, to get sufficient detail early to develop a realistic estimate and schedule, to appoint experienced operators to support the project team at the early stage of the project, to allocate sufficient funds to perform high quality front end loading and to plan the work in detail once in the field. New technologies can improve brownfield projects outcomes, e.g. laser scanning, 4D execution planning, novel inspection techniques and advanced data management.

This paper will explore what best practices reduce complexity and improve performance. Through proper framing, dependencies with other work on the asset can be minimized and this reduces the risk of delays. Transferring work from the live construction site to an offsite fabricator will lead to less safety exposure, better quality and a more predictable schedule. Performing trial fits prior to shipment further reduces the risk of execution inefficiencies.

Recognition

The recognition of the inherent complexity and challenges associated with brownfield projects at all levels of the company, will lead to better consistency in execution of this projects. Experience with executing brownfield projects and with the particular facility is a pre-requisite. Being successful at extending the life of our existing assets will then bring large rewards.