bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of a Competent Workforce for the Oil and Gas Sector
Authors: AlMatroushi Salem
Published: December 2007

The need to ensure that every task is being performed by competent workers at the right place at the right time has become one of management's top priorities. This implies the need to ensure that health-safety-environment (HSE) performance, asset integrity systems, organizational processes and staff development programs are standardized and optimized within a framework of a competency-based system. The Competence Assurance Management System (CAMS) in the Abu Dhabi National Oil Company (ADNOC) Exploration and Production (E&P) group of companies aims at addressing these issues in a structured approach. In May 2002, a multi-disciplinary Best Practice and Skills Management (BPSM) team of E&P skill pool advisors (SPA's) was assembled to build discipline-specific development frameworks (DFW's) and guidelines (GL's) documents and facilitate the CAMS implementation process. The project team worked very closely with many contributors from the E&P group of companies including skill pool technical experts (SPE's), competence assurance coordinators from human resources (CAC's) and other groups and reached a CAMS pilot implementation milestone in early 2004. The CAMS pilot involved 5 E&P technical disciplines: mechanical engineering, electrical engineering, reservoir geology, well engineering and reservoir engineering. Lessons learned from the pilot implementation were the base for optimizing the DFW's/GL's and implementation plans for 16 additional E&P disciplines to be launched in late 2004 and 2005. CAMS is initially implemented on new UAE National technical graduates to support the Emiratization targets of 50% by 2004 and 75% by 2009. Eventually, CAMS can be implemented on the entire workforce in the E&P group of companies. Additionally, and as part of the full CAMS implementation, a knowledge and learning management information technology (IT) system across the E&P group of companies is being established. CAMS DFW's/GL's include comprehensive development roadmaps, graduate development matrices, competence skill profiles, performance-knowledge-evidence criteria for every skill and detailed formal and on-the-job training programs.
Maturity Models for E&P Data and Information Management Organizations
Authors: Kozman Jess B. , Gimenez Leonardo
Published: December 2007

The maturing of the global oil and gas industry means that information resources must be effectively managed to insure a measurable impact on financial success. As the value of information technology becomes more accepted and analyzed, there is a need for a comparative measure of how organizations have advanced their information management strategies. A data management maturity model has been proposed as a method of establishing this comparison (D'Angelo and Troy, 2000). The model analyzes organizations as they move from a base level to a fully optimized structure in which data, information, and knowledge add value at all stages in a life of field project cycle. Operations are categorized into data management maturity levels by analyzing processes, technology, consistency of results, and ability to quantify value.
Opportunities for Re-Use of Produced Water around Desert Oil Fields
Authors: Sluijterman A. C. , Al-Lawati Y. , Al-Asmi S. , Verbeek P. H. J. , Schaapveld M. A. S. , Cramwinckel J.
Published: December 2007

The Greening the Desert initiative explores opportunities to re-use water produced from hydrocarbon fields in arid areas around desert oil fields. Where water does not serve any purpose for reservoir management, re-use is envisaged to be an enabler for new value creation by stimulating opportunities such as agriculture or forestry. An oil field in the south of Oman produces in excess of 200,000 m3/d of brackish water, the larger part of which is disposed of through re-injection into deep aquifers. As an alternative the operator has embarked on reed bed pilots later followed by pilots on bio-saline agriculture and forestry. Also a pilot has been executed for the purification of the effluent water from the reed beds by a Solar Dew® membrane system, allowing a.o. fresh water agriculture. Pilots for the different Greening the Desert schemes are aimed at developing a portfolio of technical solutions for produced water re-use in desert environments. The paper presents operating envelopes and limits of technical performance. The selection of technical solutions for a large-scale project may then be based on the best total lifecycle value balancing cost, benefits and risks, and meeting aspirations for sustainable development.
Learning from Three Years Annular Injection of Drill Wastes in Alwyn and Dunbar Fields in the North Sea
Authors: Onaisi A. , Po V. , Lutfalla H.
Published: December 2007

TOTAL conducted DCRI (Drill Cuttings Re-Injection) operations for discharging oil contaminated cuttings coming from the phases 12 1/4" and 8 1/2" of Alwyn and Dunbar wells, two fields situated in the UK sector of the North Sea, to meet requirements of new discharge regulations in that area. Re-injection was preferred to skip and ship based on economical evaluation of both alternatives.

Several options were considered for DCRI: annular injection into a production well, annular injection in the same well being drilled or injection through a dedicated well. The major benefit of annular injection, provided that this option is technically viable, is the saving of the cost of drilling and completing a dedicated well. Given the number of wells and the corresponding amount of cuttings that remained to be discharged in Alwyn and Dunbar, it was decided to proceed with annular injection in existing wells.

The depth of injection, the lithology, and the well deviation at that depth were dictated by the position of 13 3/8" casing shoe and open hole interval between to cement behind the casing 9 5/8". Injectivity tests were performed in the annulus of several wells1; however few of them were identified as potential injectors.

The initial design was based on the possibility of injecting up to 55,000 barrels of slurry per well. Severe difficulties were encountered during the first injections with frequent rapid loss of injectivity and total injected volume per well far below the theoretical storage capacity. A complete review of the injection parameters, mainly injection pressure and rates, and of injection procedures that include the control of slurry rheology and the way of suspending the injection annulus during DCRI shut down led to dramatic improvements regarding the injection conditions and the total volume injected in each well. This paper presents the learning from more than three years experience gained with annular DCRI on Alwyn and Dunbar fields.
Success of Complete Zero Oil/Gas Flaring and High Quality Water Discharge to Sea on Barge – Complete Achievement of HSE Guidelines
Authors: Kikuchi Shuichi , Sharkh A F. Abu , Manabe R. , Saito Teiji , Khalil Hassan I
Published: December 2007

In close collaborations with ADNOC (Abu Dhabi National Oil Company), JODCO (Japan Oil Development Company) /JOGMEC (Japan Oil, Gas and Metals National Corporation), ADMA-OPCO (Abu Dhabi Marine Operating Company), and MPS (Mansoori Production Service), ZADCO (Zakum Development Company) has developed complete Zero Oil/Gas flaring system including a WAter Treatment unit for high quality water discharge; namely ZOGWAT system based on ADNOC /ZADCO HSE guidelines.

ADNOC announced HSE goals for "Reducing or stopping hydrocarbon flaring and eliminating the dumping of contaminated water to the sea during all rigless and rig-on-site activities" in the middle of 1998. ZADCO then initiated the HSE campaign in conjunctions with ADMA-OPCO and MPS and have been challenging to attain the HSE goals by introducing several Innovative technologies of acid neutralization unit, MPFM (Multi-Phase Flow Meter), water treatment system using an adsorption media, and MPP (Multi-Phase Pump).

In 1st QTR of 2003, a complete system of ZOGWAT was successfully tested in three wells during post well stimulation/ clean up/ flow testing operations on a barge.

These trials proved that the complete system is performing effectively, i.e. no longer gas flaring and water quality problem for discharge, which would allow ZADCO achieving "Complete Zero Oil and Gas Flaring and High Quality of Water for Discharge with Oil Content less than 15ppm on Rig/Barge " in near future.

This paper highlights ZADCO's historical HSE performance of zero oil/gas flaring and water quality control for discharge on rig/barge and lesson learnt from several trials of innovative technologies as well as the campaign's contributions to environment and economical benefits.
Hydraulic Characterization of Faults and Fractures Using a Dual Medium Discrete Fracture Network Simulator
Authors: Lange Arnaud , Basquet Rémy , Bourbiaux Bernard
Published: December 2007

The presence of fractures at various scales affects the flow dynamics within a reservoir, thus casting uncertainty on the assessment of the field productivity and reserves. Methodologies and tools are now available (i) to construct geologically-realistic models of the fault/fracture network (ii) to turn these models into simplified conceptual models usable for field-scale simulations of multi-phase production methods. However a critical intermediate step remains that of validating the geometry of the geological fault/fracture network and characterizing it in terms of flow properties. This paper presents an original and multi-purpose 3D Discrete Fracture Network simulator enabling one to fulfil this hydraulic characterization step.

This simulator is based on the dual-medium concept applied to an explicit representation of the geological model of fault/fracture network and matrix medium. Large and complex fractured media in the drainage area of wells are discretized at an optimal computational cost. A rapid image processing algorithm defines locally the volume and shape of each matrix block associated with a given fracture cell. The discretization of the matrix medium can be refined using an automated procedure controlled by the fault/fracture network density. A noteworthy feature of this simulator is its capability to compute the single-phase flow response of any type of fractured reservoir, whatever the scale, density and connectivity of fractures, since both single- and dual-permeability models were developed.

After validating the present models, a realistic case that combines diffuse fracturing and major objects such as seismic and sub-seismic faults is presented. For given areal fracture densities, the fracture connectivity and the matrix/fracture permeability contrast are perturbed. The differences in well test responses between the single- and dual-permeability models are quantified. It is shown that small perturbations of the fracture properties may result in significant differences between the models responses. Some guidelines are given regarding the range of application of dual-porosity single- or dual-permeability approaches to characterize the hydraulic properties of fault/fracture network in a reservoir.
Electrical Resistivity and Gamma-Ray Logs: Two Physics for Two Permeability Estimation Approaches in Abu Dhabi Carbonates
Authors: Al-Farisi Omar , Belgaied Adel , Elhami Mohamed , Kadada Talal , Al-Jefri Ghassan , Barkawi Abdul Nasser
Published: December 2007

Permeability modeling and permeability prediction has always been a critical phase in building geological models. In a major Abu Dhabi offshore oil field, several reservoir characterization and evaluation studies have been conducted during the last five years. The estimation of permeability in each well is required to identify and model reservoir flow units in the field, Rock types are identified from cored wells using thin section and conventional core analysis (rock fabric, porosity, permeability,) in parallel with relating it to capillary pressure curves. In non-cored wells (90% of total wells), a backward model of rock type classification is achieved through the utilization of well logging data which is proved to provide (1) Porosity & (2) Lithology information using Neutron, litho-Density and Sonic tools, therefore, Permeability from logs is the missing information to make the log rock typing backward model working.

In these studies, several innovative approaches of permeability estimations have been developed in-house and used or declined in different stages. Two of these approaches will be thoroughly explained to explore the strengths and weaknesses of each one of them with the reasons of being working in some formations but not others, where different relations between Core permeability and Log responses in different formations is driven by rock properties.

In the first approach, the invasion profile permeability index from Electrical Resistivity logs has been used to honor the general relation between porosity and permeability, in which six different cases and conditions has been considered to correct for the universal equation developed in this approach from logging data of Electrical Resistivity, these consideration are: (1) gas zone, (2) oil & transition zone, (3) water zone, (4) fractured area (5) drilling fluids (6) facies quality. This permeability estimation approach is called Universal Rock Permeability (UROK).

In the second approach, the clay content distribution constructs the permeability alteration model that is reflected in Gamma-Ray (GR) response, where GR horizontal changes within a layer found to be different from another layer. Therefore, a statistical GR analysis that searches for the optimum GR-Permeability model is developed. This permeability estimation approach is called Permeability Active Searching (PASZ).
Image Enhancement, Automated Interpretation, and 3D Visualization of Borehole Image Logs in Characterization and Calibration of Fractures in Kuwait
Authors: Wu Haiqing , Al-Anzi Menahi , Ammar Heyam Muhammed , Ameen Meshary , Qidwai Moinuddin , Lomando Anthony
Published: December 2007

New techniques have been developed for image logs to enhance image quality, improve vendor's interpretation, identify geological features, and visualize both image log and interpretation in a 3D environment.

These techniques are quite useful to handle poor image due to oil based mud and heavy mud weight in deep exploration drilling, and can be applied to all commercial borehole image logs such as CAST, CBIL, Earth Imager, EMI, FMI, OBMI, STAR, and UBI.
Reservoir Facies Prediction from Geostatistical Inverted Seismic Data
Authors: Barens Leon , Biver Pierre
Published: December 2007

The estimation of oil in place in a reservoir is a key element in reservoir management. Based on these estimations, economical decisions can be taken. Therefore, it is necessary to take into account all possible sources of uncertainty in reservoir characterization. To address the uncertainty from seismic inversion, we use pre-stack geostatistical inversion to arrive at a family of related IP and IS volumes. The geostatistical inversions explore the possible elastic subsurface models that are constrained by the seismic and well data together with geostatistical modeling parameters. These IP and IS volumes are transformed to a family of seismic facies volumes with the use of a well data derived cross-plot. On the cross-plot, seismic facies regions are interpreted while each seismic facies region contains points of the well identified geological facies. The seismic facies models obtained from the inversions are used to obtain geological facies models. To arrive at such a model, the uncertainty in the points sampled by the well is used to define thresholds for a truncated Gaussian simulation. In this manner, the uncertainties from the seismic data inversion are propagated to the geological facies model. With the availability of probability functions for the petrophysical parameters and the volumes of the reservoir grid cells, the oil in place can be computed. Repeating the procedure for each seismically inverted data volume, a histogram of the oil in place is obtained in which the uncertainty from the seismic inversion is propagated to a geological facies model which can be utilized in an integrated oil in place calculation.
Well Integrity Management System (WIMS)
Authors: Al-Ashhab Jamal , Afzal Mohamed , Emenik Cornelius O.
Published: December 2007

ZADCO owns more than 500 wells operating in UZ, UA & ST fields to contribute in achieving the production targets as set by the Shareholders. To ensure that wells operate as designed for their assigned life (or greater) with all risks kept as low as reasonably practicable or as mentioned, it is important to insure individual well's integrity. Hence, ZADCO developed an in-house "Well Integrity Management System (WIMS)", which defines & provides the operating standards & guidelines for maintaining the well integrity parameters, ensuring safe well operations and securing well potential availability during its life cycle so that return on investment is maximized without the sacrifice of safety and environment.

The implementation of ZADCO's well integrity process follows the cycle assurance testing, preventive measures, monitoring, evaluation / assessment, control & remedy, audit / verification.

This paper reviews WIMS in ZADCO. WIMS is structured to include wellhead (surface) equipment, downhole equipment and operational (process control). WIMS places much emphasis on the requirement of barriers for safety and environmental protection.
Modeling Mud Loss in Fractured Formations
Authors: Lavrov Alexandre , Tronvoll Johan
Published: December 2007

A theoretical framework is developed for the apparent borehole ballooning phenomenon in naturally-fractured formations caused by the loss of a power-law drilling fluid into an isolated non-propagating deformable circular fracture of finite dimensions. A borehole ballooning/mud loss equation is derived and solved numerically. Effects of formation properties (formation fluid pressure, fracture extension and aperture) and operational factors (mud weight, mud rheology, borehole diameter) on mud loss dynamics are studied. Application potentials of the developed modeling approach are explained.
Observations and Lessons Learned from a Set of Production Logging Data in Horizontal Barefoot Completions
Authors: Al Hamawi Mohamed , Al Arfi Saif , Elkadi Antoine , El-Itawi Ghina
Published: December 2007

Production logging in horizontal wells is not an easy task. The usual purpose is to determine the flow or injection profile in general and identify the fluid entry or intake points along the survey interval of the well trajectory. When the completion is barefoot the operation becomes a challenge; all the job aspects must be carefully planned and prepared.

This paper investigates the production logging jobs that were performed in 22 open hole horizontal wells (18 producers and 4 injectors) in two onshore fields in the United Arab Emirates in the past couple of years. The various phases and aspects of the jobs were carefully evaluated and several conclusions have been drawn. These conclusions involve: 1-The conveyance method; the choice between a wireline tractor and coiled tubing, the correctness of the conveyance simulation and the success rate.2-The choice of the sensors to run as a function of the objectives and downhole conditions (e.g. running a well deviation sensor in the tool string has proven to be very useful).3-The logging program; the sequence of acquisition can be optimized to minimize the number of passes and acquire the most important data first.4-The influence of the operation techniques on the data quality (e.g. the choice of the station depths, the logging speed, etc).5-The interpretation of the acquired data; the quality control of the data is of paramount importance. The weight to be assigned to each sensor in the solution must be carefully chosen, the error bands on the curves or the accuracy of the measurements must be well understood and taken into consideration.

The lessons learned from this study, from the job design to the interpretation of the results, can be applied to future horizontal well logging jobs to acquire higher-quality data and yield better interpretation results.
Testing the Mobility of Oil below the OOWC of a Multi-layered Matured Clastic Reservoir in North Kuwait: Tapping the Reserves & Production Growth Opportunity
Authors: Chetri HB , Al-Ajmi Moudi , Khan Ali Nasar , Al-Mutawa Majdi , Al-Hajeri Noura , Al-Janaie Dalal , Al-Mayyas Nouf , Al-Anzi Ealian
Published: December 2007

Lower Burgan, a giant clastic reservoir in Sabiriyah field of North Kuwait was discovered during mid 50s (Location map shown in Figure-1). An integrated performance analysis recently carried out indicated that the reservoir has a much higher potential than anticipated earlier. Though the cumulative recovery till date was more than 70% of the initial recoverable reserves, the reservoir pressure decline was insignificant with average water cut of about 20% only in this active water drive reservoir. Significant additional open hole data in new well penetrations, cased hole log data, seismic reinterpretation, additional production performance and pressure data acquired since last major reservoir update in 1998, has considerably improved the reservoir potential understanding of Lower Burgan.

Although reservoir performance suggested possibility of larger STOIIP base, lack of sufficient mapped net pay area impacted the deterministic STOIIP estimation negatively in the past. The additional information obtained in the new wells has opened up a large additional pay area by way of structural refinement, lowering of OOWC and additional net sands mostly in L-member. Whilst number of wells drilled in southwest flank and in north and south indicated possible occurrence of a deeper OOWC than earlier interpretations, SA-X1, the well drilled and tested beyond the reservoir limit in southern area, produced dry oil from sands with high Sw.

In order to assess the full potential of new reservoir area and to test the mobility of oil below the hitherto OOWC, a detailed testing program was formulated and implemented. MDT sampling was undertaken at several wells with successful results to prove the mobility of oil. Rigless perforation/ testing job were done at one of the identified wells, showing only traces of oil. Cores were cut with full suite of open hole logs and the RFT data. Production testing at newly completed wells, long term build up tests, PLT data and RST logs confirmed the additional potential for this mature reservoir, which was supposed to be on decline as per earlier predictions.

The paper is a classic example as to how a mature reservoir has been re-assessed and brought to the development limelight in terms of enhanced STOIIP, Reserves and production.
Reservoirs A & B Gas Injection Pilot - Monitoring Logging and Uncertainties
Authors: El Hamawi Mohamed , Al Arfi Saif , Efnik M. , Petricola M. , Namboodiri K. M. N.
Published: December 2007

In this paper, we will first estimate the uncertainty on remaining oil saturation S_oil during primary water flooding, since that is the maximum saturation that remains available for enhanced recovery through gas injection, and this number plays a critical role in the original decision on whether to even initiate a gas injection pilot project. We will then confirm the findings of reference 1, as to the final S_oil after gas injection, but will also look at the variations in S_oil uncertainty as the gas volume increases from initial breakthrough to final maximum saturation. The situations of gas displacing oil in an unswept reservoir, and gas replacing both oil and water in an already water-swept reservoir will be considered.

Planning and designing the gas injector and observer is a key for the gas pilot success. Results of two gas injection pilots is discussed.
Formulation of "Capillary Force Barriers" in Moderately-Oil Wet Systems and Its Application to Reservoir Simulation
Authors: Muneta Y. , Mubarak M. , Alhassani H. , Arisaka K.
Published: December 2007

As a common production aspect of Thamama formation (carbonate reservoir), in both onshore and offshore of Abu Dhabi, unexpected early-water breakthrough through specific high-conductive zones has been observed in several water injection schemes. Observed field data, such as PNC logs, indicated non-occurrence of injected water slumping away from well bores. A concept of "Capillary Force Barrier" was introduced several years ago to tackle this issue, in which the role of capillary force on cross flow in stratified layers is modeled1,2,8.

This paper tries to revisit and fine-tune the concept in hysteresis of a moderately-oil wet system. In this attempt, firstly, some synthetic measurements of special core analysis and the interpretations are presented, in which the results are analytically formulated by a published methodology to generate saturation functions consistent with the hysteresis under an assumption of wettability5.

An application to numerical reservoir simulation was carried out in a systematic manner, as the Reservoir Rock Type (RRT) scheme of the model was based on primary drainage curves that can be fully linked with the generated saturation functions. It is demonstrated on cross sections how small difference in imbibition capillary pressures can affect the water movement through complicated RRT contrast in moderately oil-wet system.

The proposed formulation is a powerful tool for generalizing saturation functions as matrix properties in a consistent manner and open door to systematically incorporating not only hysteresis but also wettability into the numerical reservoir simulation model.
Wetting Fim Effects on Steady-State Two-Phase Fow in Pore Networks using the DeProF Theoretical Model
Authors: Vaavanides Marios S. , Payatakes Alkiviades C.
Published: December 2007

The motion of oil ganglia and droplets in chamber-and-throat pore networks in two-phase flow in porous media can be modeled without or with wetting films. The existence of wetting films around ganglia and droplets is favored by small contact angles (say, smaller than ca. 10 deg) and wall roughness.

The predictive model DeProF (Decomposition into Prototype Flows) considers steady-state two-phase flow in porous media as a composition of three flow patterns, namely connected-oil pathway flow, ganglion dynamics and drop traffic flow. The key difference between these prototype flow patterns is the degree of disconnection of the non-wetting phase (‘oil’) which, in turn, affects the relative magnitude of the rate of energy dissipation caused by capillary effects compared to that caused by viscous stresses. The observed flow is usually a mixture of the basic prototype flows.

In the present work DeProF is used to investigate the effect of the wetting film on two-phase flow in typical 3-D pore networks by including wetting films around droplets. The effects of the wetting film are assessed by comparing the values of key physical characteristics of two-phase flow, specifically, the interfacial area per unit volume, the mechanical power dissipation p.u.v., the degree of disconnectedness of the non-wetting phase, and the energy utilization factor, which are obtained with and without wetting films.
Two Generations of Thermal Decay Tools: A Comparison in a Common, Friendly, Borehole Environment
Authors: Boyd Doug , Al-Hendi Ahmed , Al-Farisi Omar , Okuyiga Moyo
Published: December 2007

Abu Dhabi National Oil Company (ADNOC) and its group of companies completed a review of logging practices in Feb. 2000.1 A recommendation was made to compare PNC tools in a properly characterized well under controlled conditions. This report addresses that recommendation by comparing the accuracy, repeatability and reproducibility of two new and two older generation PNC tools currently available for field monitoring in Abu Dhabi reservoirs. Tools are compared against each other and to core measurements. Elemental analysis of core and reservoir condition fluids provided the benchmark for formation capture cross-section comparisons. One tool displayed much poorer statistics than the other tools. All tools suffered from large inaccuracies in their auxiliary porosity measurements. Reproducibility was good for sigma measurements but poor for porosity. Three of the four tools are acceptable for qualitative field monitoring operations. Two of the tools are preferred for accurate residual oil measurement.
How to Manage and Produce from a Low Permeability Zone in a High Permeability Contrast Reservoir
Authors: Talabani Soran
Published: December 2007

The most difficult practice in the oil industry is to displace oil in the low permeability zones in a heterogeneous reservoir. This situation becomes worse when the permeability contrast is high and is hydrocarbon properties dependant. In this study, experiments were conducted to investigate on how to temporarily plug the high permeable zones and flood the low permeable zones within the reservoir. Plugging the high permeability zone temporary is important because fluid segregation might complicate the outcome of production management.

Different permeability contrasts of rock samples were used in the experiments. These experiments were conducted in the presence of one type of oil followed by water injection, while injection fluid properties, quality, injected slug size and velocity were controlled.

Results show that the injection of mixed surfactants-fluid followed by water could stand plugging the high permeability zone and diverting water injection into the low permeability zones. Though, the mixture should be pumped with certain pore volume. Only some specific surfactants-fluid mixture (not used in the oil industry) resulted in stable fluid for the diversion process. When water was followed by the mixture, most of the oil in the low permeability zones were removed and flowed out of the rock. Certain slug sizes were needed in different permeability contrasts. As a result of the experiments, an easy way was observed to predict fluid rate and quality from laboratory experiments before the application in the field. Field application confirmed the lab experiments and higher production rate were managed.
Occupational Health Program - Integrated Medical Information System (IMIS)
Authors: Bakinson Mohiedeen A. A. , Al-Mandhry Ali S.
Published: December 2007

A quality improvement project by the Medical department identified the need of an integrated computerized system to support and improve the Medical department's processes and also modernize the running of the department. GERMS was the proposed Shell Medical information system at the time and it was looked into and found to fall short with the PDO requirements. Third party packages were then evaluated and led to the birth of a customized IT system which was named as Integrated Medical Information System (IMIS).

This paper will describe this system and highlight the Occupational Health Module which has been the bed rock of information for Medical and Health Safety & Environmental reporting in PDO. Further improvement to IMIS is planned to provide facility to monitor and identify staff who not be complying with the recommended frequency of medical examinations, as well as manage health of staff who may have work/location restrictions due to results of medical examinations.
Implementations of New Technologies for Oil and Gas Industry
Authors: Shaker Moh'd Mamdouh , Moh'd Hussain Ali
Published: December 2007

Deflecting Conductor Sleeve "DCS" is a slot recovery tool that proved a valuable system for the economical salvaging of the previously used slots of the offshore platforms in the late development stage. It is used when there is a need to drill infill wells while most of the platforms' slots are already used, and installing new platforms or making extension for the existing platforms are not justified.

Dynamic Surge Device "DSD" is a sub, normally installed below the production packer on the bottom of the completion string acting as a blanking plug to set the packer, test tubing and automatically unload the well without any need to the risky wire line operations.

Lifting Platform "L.P" is a hydraulically operated lift platform to provide additional storage area and to facilitate the movement of heavy equipment while working on the main platform (tower).

Solvent Injector "SI" is developed to clean the gas lift mandrel and valves by injecting only the required volume of solvent around the valve, avoiding unnecessary dripping volumes of the solvent to affect other parts of completion.

Jack-up Mover Assistance "JMA" is a special technique which uses a prefabricated floating concrete breakwater in front of the offshore platforms at the rigs' approach side, providing protections to the rig from waves during jacking up and down at rig approach and move, minimizing waiting on weather time and saving lots of money. The system is still under development.
Back Allocation System with Network Visualization
Authors: Hamad Marwan , Sudharman Satheesh , Al-Mutairi Ali
Published: December 2007

The use of Back Allocation is crucial in the Oil and Gas industry to facilitate accurate allocation of actual production and injection volumes at every node of a production network. Production engineers frequently use back allocation to estimate actual production volumes from wells based on frequent well test data or theoretical calculations using well and reservoir characteristics.

ZADCO implemented an optimized back allocation system to cope with the growing business needs, after a thorough system study of the legacy back allocation system. This presentation will present the considerations that led to this implementation and the project success.

ZADCO is a major operating company in Abu Dhabi operating in offshore fields, and is one of the largest oil companies in the world. Being a highly productive operator, ZADCO needed a back allocation system for apportioning fluids among upstream sources within a production network.

The new system provides a means to visualize complex networks, verify the production streams, track gathering systems functionality through time and derive the allocation networks.

This project has proven to be a reliable and comprehensive back allocation system, capable of providing all the necessary features required for a robust and solid back allocation system.

After the new Back Allocation System became fully operational, ZADCO started to realize the following benefits from this successful implementation. Ability to correctly apportion production, where accurate measurements are not possible or cost effective.Ability to determine fluid flow quantities through every strategic point in the network and determine the production quantities of each well and reservoir for production accounting.Reduced time and effort to setup and execute fluid disposition allocations.Better quality back allocated resultsThe new system optimizes the allocation system workflow, resulting in the routine monthly allocation work being greatly simplified.
Development and Applications of Sustaining Integrated Asset Modeling Tool
Authors: Liao T. T. , Lazaro G. E. , Vergari A. M. , Schmohr D. R. , Waligura N. J. , Stein M. H.
Published: December 2007

An enabling application tool was developed for updating and maintaining Integrated Asset Models (IAM) for production optimization, surface network debottlenecking, and production allocation. The tool automates the routine tedious tasks required to update and maintain large-scale IAM models. Application of this tool in many BP Business Units (BU) consistently resulted in about a 90% reduction in model maintenance and management time, streamlined the IAM model application process, and improved production allocation accuracy. Deployment of this tool in the last few years has brought a step change to IAM model application across asset teams within BP.
Modeling and Validation of Initial Water Saturation in the Transition Zone of Carbonate Oil Reservoirs
Authors: Ghedan Shawket G. , Thiebot Bertrand M. , Boyd Douglas A.
Published: December 2007

The modeling of initial water saturation distribution in simulation models could be achieved by one of two techniques. The upscaling the log interpreted water saturation distribution of the finer 3D geological model constitutes the first technique. The challenge in this technique is to accurately describe the important rather thick transition zone of carbonate reservoirs. A large and non-achievable number of control points (wells) are needed. Rock type controlled restored state oil-brine capillary pressure, Pc, curves is the second technique. This results in an accurate picture of oil reserves providing that the rock types are distributed correctly. Significant numbers of oil-brine Pc measurements are needed however, to address all rock types, wettability, porosity and permeability ranges.

Frequently, not all the necessary Pc curves are available. To fill this gap, reservoir characterization data along with log-derived water saturation, Sw, data are utilized to generate representative Sw-height functions for all rock types of a carbonate oil reservoir. Only cored wells are employed, ensuring the most accurate rock-type profiles. To match the span of Sw at a given depth, sorting by porosity, permeability and reservoir quality index within each rock type is carried out. Describing the large span of log-derived Sw in the transition zone is especially challenging.

The technique assumes the log-derived saturations are correct and emphasize the need for laboratory tests of resistivity indices and cementation factors representative of the dominant rock types for accurate log interpretation.

The attainability of a good matching between the log-derived and the Pc-derived Sw and bulk volumes of water depth profiles for the cored and un-cored wells validated the modeling process. This is supported by statistical analysis and mapping of the water saturations in all layers of the simulation model.
Gel-cement, a water shut-off system: qualification in a Syrian field
Authors: van Eijden Jip , Arkesteijn Fred , Akil Ihab , van Vliet Jacques , van Batenburg Diederik , McGinn Paul
Published: December 2007

Water production in the North-east of Syria has increased significantly in recent years. As a result costs per barrel of oil have increased and the field's production is currently constrained by the facilities capacity.

PLT surveys combined with a reservoir study showed that good-quality sands were not properly swept by the water, probably due to poor connectivity in the reservoir. It was anticipated that these un-swept sands could contribute to production if the watered out sands were shut-off.

A newly developed gel-cement has been used to shut-off the watered out sands in a cost-effective manner. The gel-cement system combines the properties of two shut-off techniques: ■Cement for mechanically strong perforation shut off.■Gel for excellent matrix shut off.

The gel, used as ‘mix water’ of the cement, will be squeezed into the matrix creating a shallow matrix shut off. The cement will remain in the perforation tunnel as a rigid seal. This system showed superior shut off performance in the laboratory compared to normal cement squeeze techniques. Selective perforation of the hydrocarbon zones will reestablish the oil production. The shut off zones can be reopened later in the well's life when artificial lift has been installed.

In the first field trial 84 meters of perforations (gross) were squeezed of with the gel-cement in a single attempt. After re-perforation of the top and the middle zone the well produced at a strongly reduced water cut, i.e. 25–33% compared to 60–62% before the treatment, and an increased oil production, i.e. 3000 bopd compared to 1000 bopd before the treatment. The oil production declined to 2000 bopd over a year. The water cut gradually increased over that period to 56%.
Maturing Field: A Case History Offshore Abu Dhabi
Authors: Glière L. , Brun B. , Bure E. , Ryan M. , Jasmi A. Al
Published: December 2007

The field is a very mature field. 30 years after its production start-up, it is now producing with an average water-cut of 84 %.

This paper presents the continuous adaptation efforts deployed throughout the years to further valorise resources, in response to the growing maturity of the field.

Well activation started very early, first through ESP's, then by full field gas-lift implementation. As an answer to an important depletion of some reservoirs, a water injection scheme has been implemented as early as 1979. In 1997, a major field revamping campaign was performed to implement an EOR technique which proved to be very efficient: tertiary gas injection after water flooding. After the first horizontal wells, drilled in 1994, ever increasing well architecture complexity allows now to target more and more precisely heterogeneities, to produce residual oil pockets, and to develop tight reservoirs. A 3D seismic acquired in 1995 has opened the path for quadruple and quintuple multilateral wells.

At the current maturity level, field management appears as the next challenge. The complex gas scheme, which comprises at the same time gas production, gas lift, gas injection, gas recompression and gas export, needs constant arbitration between activation gain and tertiary recovery.

In parallel, a global water management policy must be set up, as the water disposal network is more and more heavily loaded. A water management study is currently under the way, to review long term fluid production predictions, surface facilities limitations, and long term reliability of disposal well, and to screen for solutions, ranging from reservoir and well control to surface facilities de-bottlenecking.
Re-Birth of a Mature Carbonate Gas Pool
Authors: Carr K. C. , Fiori M.
Published: December 2007

Operation of a mature pool requires increasing cost control and infrastructure optimization and consolidation to maintain profitability. The decision to initiate this type of reservoir management plan, sometimes described as harvest, is driven in part by reservoir performance analysis and in part by commodity prices at the time the decision is made. The impact is not limited to operating cost; it can affect reservoir performance itself and the ultimate recovery of reserves.

This paper presents the account of a 3.7 TCF sour gas pool in Alberta, Canada and the technical impact of harvest on field operations, reservoir performance and ultimate recovery. The combination of new production decline analysis, well work-over with surprising results, and key field observations led to a complete change in reservoir interpretation. A new model emerged where near wellbore regions are deeply damaged and the gas-water contact (GWC) is much lower than expected.
Waterflood Strategy – Challenges and Innovations
Authors: Bibars O. A. , Hanafy H. H.
Published: December 2007

More than thirty years ago, Gulf of Suez Petroleum Company (Gupco) - Egypt, initiated the first waterflood project for El Morgan oil field. The company now operating 14 different waterflood reservoirs. These reservoirs have produced a cumulative oil representing 40% of their original oil-in-place. On average, the projected waterflood recovery factor is 54% of OOIP. Due to non-uniform lithology and non-uniform pattern of existing well locations in most reservoirs, peripheral waterflood was found to be the most suitable and economic waterflood pattern at project startup. Peripheral waterflooding has the advantage that it minimizes the number of injection wells by converting the watered-out producers. As these reservoirs become more mature, the line-drive pattern (peripheral + internal injection) was found to be more effective. Since most of the reservoirs are currently in the mature stage, good managing and close monitoring for each waterflood project is extremely important. This paper presents major strategies in managing the different waterflood projects to maximize both the oil production rate and oil recovery in optimum manners. This is being achieved through several common and familiar waterflood issues including in-fill drilling, zonal injection improvement, injection pattern modification, injection below formation parting pressure, pressure maintenance, workovers for production and injection wells, continuous data collection, and water quality monitoring. The paper also addresses the waterflood side effects such as scale buildup, reservoir souring and facilities corrosion. In addition, the paper discusses some of the innovative techniques that have been used to maximize waterflood recovery and enable waterflooding of marginal fields at a cost effective manner. Examples for these techniques are gas-cap water barrier injection, heavy oil waterflooding, coiled-tube water injection lines, slim-tube dual completions, and satellite waterflooding for pilot and marginal fields waterflooding.
Study of Compositional Processes in Oil Recovery from Andrew Field due to Submiscible Gas Injection
Authors: Mirzaei M. , Khamehchi E. , Clifford P. J.
Published: December 2007

This study is part of a development study to investigate the mid and late life options for the Andrew Field. The focus was placed on the benefit of Compositional Simulation compared to the Black Oil Simulation in predicting the recovery of condensate from gas cap and residual oil in water-invaded area of oil-leg. The impact of converting a former horizontal producer, which has been shut in for a period of time due to high water-cut, to gas injection was considered.

One dimensional (1D) simulation models of the oil-leg were used to ascertain the Minimum Miscibility Pressure (MMP) with injected gas and the nature of displacement mechanism. Different grid block dimensions were used to consider the effect of numerical dispersion on MMP. A pressure of about 6000 psi, significantly higher than current reservoir pressure, would be needed to produce a fully miscible system. A Minimum Miscibility Enrichment (MME) analysis was carried out whereby a conceptual addition of 50:50 mixture of C3:C4 components in terms of molar proportion as NGL was added to the injected gas stream. NGL enrichment of 35% and above results in a miscible injectant at saturation pressure. Strongly vaporising gas drive process dominates in all cases and therefore continuous injection of lean gas will provide sub-miscible displacement of residual oil.

1D Compositional and Black Oil Simulation models of the gas cap region were used to measure the condensate recovery of the gas cap under different possible depletion scenarios. Condensate recovery due to primary depletion is 40% whilst different gas injection plans have resulted in higher condensate recovery, an average around 85%.

Three dimensional (3D) Black Oil and Compositional sector models of a pattern element were used to investigate the benefit of converting a producer to a gas injection well, to mobilize the residual oil in the water-invaded area. Results indicate substantial residual oil vaporization and condensate recovery by Compositional model, which is not predicted by the Black Oil model.

There is reservoir heterogeneity due to the different structural setting and faulting in upper and lower hydrocarbon bearing units. Injecting to upper unit rather than the lower unit maximizes condensate recovery. Residual oil recovery by injecting to the lower unit is higher than the upper part due to higher residual oil saturation to water sweep and larger gas flooded area. This provides an important justification for gas injection, particularly into the lower unit.