bluuebunny/crossref_metadata_2025 huggingface dataset:
Geological Framework Modeling and Rock Type Optimization for a Giant Oil Field, Offshore Abu Dhabi
Authors: Neo Sadafumi , Asada Jiro , Fujita Nozomi , Mohammed Salman , Arab Hani
Published: December 2007

Reservoir characterization study was conducted to build a realistic 3D flow unit model for Thamama II carbonate reservoir by clarifying geological factors controlling highly heterogeneous permeability distribution in this reservoir.

Algal micritization was found as a key geological factor of this reservoir leading to both rock type optimization and geological framework modeling. Petrophysically, algal micritization alters grain type and pore type thoroughly by creating abundant micro-pores within grains and closing intergranular macro-pores due to easy compaction of softened grains. In terms of distribution, such algal micritization is significant mainly in a shallow shoal area according to recent carbonate analogue from offshore Abu Dhabi. A total of 10 lithofacies was defined based mainly on the composition of newly defined 8 grain types, which represent distinct micro-pore distribution, physical property and depositional environment.

Pore throat size distribution curve analysis shows that peak pore throat size from SCAL data fairly matches with calculated pore throat size using Winland equation. Petrographical and petrophysical evaluation led to fair to good poro-perm regression to a Flow Zone Indicator (FZI) curve for each lithofacies, which is reasonably explained by a unique composition of different pore types in each lithofacies. These lithofacies were further grouped into 6 rock types by FZI value.

Areal distribution of these lithofacies shows aggradational stacking pattern and abrupt lateral change particularly in Lower IIB-IID. This rather matches with detached rimmed carbonate shelf model controlled by a NW-SE trending shoal and tidal channel system, contrary to the conventional understanding of progradational carbonate ramp model for this reservoir. Two high permeability lithofacies composed of non-micritized grains and intergranular pores were recognized lying along tidal channels.

Permeability maps were preliminarily generated for key layers using lithofacies/rock type maps, unique FZI value for lithofacies/rock type and log porosity. Further optimization of rock type with relatively poor FZI regression is planned in the next phase to accomplish better match among predicted permeability, core permeability and dynamic data.
A Geostatistical Approach to Attribute Interpolation Using Facies Templates, an Advanced Technique in Reservoir Characterization
Authors: Alqassab Hisham M. , Heine Christian J.
Published: December 2007

Reservoir characterization is considered a crucial step for fluid flow simulation studies. The need for quantitative, detailed and sound geocellular models that can simulate the effect of reservoir heterogeneity has become increasingly important in recent years.

This paper focuses on a geostatistical approach, using geology and seismic derived templates from an eolian depositional environment to produce a high resolution 3-D geocellular model.

Hawtah-Field of Central Arabia, which demonstrates an eolian environment of deposition, is used as an example. Two facies are present with different facies distributions, namely a high quality reservoir dune facies which has a dominant east transport direction and a non-reservoir inerdune facies which has an isotropic distribution. Directional variograms are used to capture both trends and continuity of each facies within defined stratigraphic sequences.

Directional variograms are then used in building 3D facies models using indicator algorithms utilizing log-derived facies and geological templates for each of the thirteen stratigraphic sequences. The geological templates, based on borehole image and seismic amplitude data, are used to derive varying azimuth and anisotropy which variograms can't accomplish alone.

Finally, sequential gaussian simulation is selected to construct a quantitative, high-resolution reservoir model of porosity and permeability based on facies. These models will honor data at the wells in addition to maintaining facies variations observed in the interwell vicinity constrained by geological templates. These models will then be ready for fluid flow simulation and ultimately for reservoir performance predictions upon which to base reservoir management decisions.
Integrated Reservoir Characterisation of a Giant Lower Cretaceous Oil Field, Abu Dhabi, U.A.E.
Authors: Jürgen Grötsch , Omar Al-Jelani , Yousif Al-Mehairi
Published: December 2007

In the framework of the integrated reservoir characterization study (IRCS) for a giant Lower Cretaceous oil field in Abu Dhabi, a key deliverable was a sedimentological and diagenetic model of the field to be used as input for 3-D geological modeling of the stacked reservoir zones. Integrated 3-D reservoir characterization in carbonate fields is a topic of ongoing discussion whereby data preparation, data requirements, as well as actual static and dynamic modeling procedures vary considerably in the industry, in general, and from field to field, in particular. One of the more often raised issues is the link between bio-facies based models incorporating depositional and sequence stratigraphic characteristics and their link to the 3-D petrophysical property distribution. In this paper, the concept of reservoir rock type based modeling is introduced as a missing link between static and dynamic modeling. Such rock-type based 3-D models can equally provide vital input for further seismic and geo-mechanical modeling.
Optimization of Well Completion in Water Flooding Pattern Using Flexible Grid Simulator
Authors: Takahashi Shunya , Kuwauchi Yusuke , Yamazaki Noboru
Published: December 2007

This paper described a simulation case study on an infill well in a water flooding pattern. A 3-Phase, 3-Dimensional • flexible grid simulator, namely VERDI-3D which was developed by Technical Research Center of Japan National Oil Corporation, was used to study the oil recovery performance for various well completions and optimize the direction of lateral hole. The study assumed an actual carbonate reservoir in Middle East having heterogeneous characteristics. In a history matching phase, simulation was conducted using a combined grid system i.e. radial grids around vertical wells and Cartesian grids as a background. In a prediction phase, flexible grids were newly defined and superimposed over the original grid system according to the type and trajectory of the infill well. The variable parameters such as pressure and water saturation values were reallocated for the new grid system. Then the model was restarted to predict the well performances. Same case study was conducted using a commercial simulator ECLIPSE and the results were compared with those of the VERDI-3D. Based on this case study, the applicability of VERDI-3D to actual field problem was confirmed.
Short Term Analysis of Wells with Finite Conductivity Fractures Using Simultaneously Measured Transient Pressure and Flow Rate
Authors: Almehaideb R. A. , Abou-Kassem J. H. , Osman Mohammed E.
Published: December 2007

Analyses of variable flow rate tests have been given special attention recently because it is generally impractical to keep a constant flow rate long enough in the field to perform a drawdown test. Also, in many other situations, the early time data are usually affected by wellbore storage. For fractured wells, this early time period represents linear or bilinear flow in fractures. Thus, it is very important to devise a technique that would allow a petroleum engineer to obtain reservoir in addition to fracture characteristics such as fracture conductivity and fracture half-length, using this early flow data.

In this paper, a new mathematical model is developed to describe drawdown and buildup tests for wells intersected by finite conductivity fractures. This new model utilizes the convolution method to arrive at a solution for downhole pressure versus time using simultaneously measured downhole pressure and sandface rates. Analysis based on the solution of this new model allows one to calculate directly both reservoir and fracture characteristics. Results obtained are verified by solving two field examples to demonstrate the model capabilities. A step by step procedure for analysis is also presented.
Case Histories Of Successful Water Shutoff Techniques Utilised In Enhancing Oil Output From Minagish Oolite Reservoir Of East Umm Gudair, (West Kuwait).
Authors: Chawla M.L. , Al-Otaibi Abdullah , Waheed Arshad
Published: December 2007

This paper was prepared for presentation at the 8th Abu Dhabi International Petroleum Exhibition and Conference held in Abu Dhabi, U.A.E., 11-14 October 1998.
A Proactive Approach to Address Solids (Wax and Asphaltene) Precipitation During Hydrocarbon Production
Authors: Jamaluddin A.K. M. , Sivaraman A. , Imer D. , Thomas F. B. , Bennion D. B.
Published: December 2007

The identification of conditions at which the first crystal of wax or asphaltene appears is the first step toward seeking any remedial options. Various procedures exist in determining the onset of wax and asphaltene precipitation conditions. Among these various processes, acoustic resonance technology (ART) is a newly developed method for the highly accurate non-optical determination of phase transitions in high temperature and pressure reservoir fluids. The acoustic resonance experiments were conducted under a depressurization mode to detect the onset of asphaltene precipitation at a fixed experimental temperature. During the depressurization runs, acoustic features corresponding to the onset of asphaltene precipitation or solid-liquid equilibrium (SLE) conditions were detected as the system pressures were decreased from reservoir conditions. Subsequently, during the same run, the acoustic features were also detected that signified the vapor-liquid (VLE) equilibrium conditions. In addition, isobaric cooling experiments were also conducted to identify the onset of wax precipitation. The isobaric cooling experiments detected the features corresponding to wax precipitation (SLE) conditions.

Results defining the SLE and VLE conditions of reservoir crudes containing asphaltenes and wax are extremely promising. Comparison of the VLE data obtained using ART with that obtained using an optical method showed excellent agreement. In addition, comparison of SLE data obtained using ART showed excellent agreement with that obtained using a light-scattering technique where the light scattering technique is applicable.
New Results In Real Time Vibrations Prediction
Authors: Perreau P. J. , Rey-Fabret I. F. , Gomel M. M. , Mabile Cl. M.
Published: December 2007

The real time MWD system-named TRAFOR-X and developed by IFP is able to scan synchronously and to analyse 24 real time downhole and surface sensors while drilling. It has been applied to a large range of research activities in the drilling and the geophysics domains. With the help of this tool, a new method has been developed to estimate real time downhole measurements like bit RPM or WOB using the sole standard surface measurements. These estimations result in the prediction of some main abnormal vibrations such as stick-slip, bit-bouncing or whirling.

A dozen of field experiments using TRAFOR-X has led to the creation of an important database. The prediction of the abnormal bit vibrations and the efficiency of the estimation of the downhole measurements have been tested successfully against this database. In 1997 the procedures to predict the stick-slip have been implemented in a dedicated mud logging system named ALS-EVE containing its own alarms management system. Numerous field tests using both the TRAFOR-X and the ALS-EVE have proven the effectiveness of the procedures. The alarms have allowed an instantaneous warning when stick-slip occurs.

The real time stick-slip prediction is one of the first implementations of smart alarms in mud logging systems. The next steps are in progress, such as real time bit bouncing prediction and whirling detection. The whole study is part of the « DO-IT Drilling Operations Interactive Technologics ™ » initiative.
New Cementing Technique for Khuff Gas Wells
Authors: Zaghaty S. Zaki El , O'Driscoll K. P.
Published: December 2007

Khuff gas wells in the Arabian Gulf have been notoriously difficult to cement successfully, with many wells suffering from pressurized annuli and inter-zonai communication. The root cause of these problems stems from low fracture gradients particularly in the Mishrif formation where losses occur at very low mud weights.

In the past setting casings across these critical zones has been done using stage cementing collars and conventional cement slurries and has resulted in many failures due to losses and stage tool malfunctions.

The use of computer aided design and the correct application of lightweight cement systems has enabled this type of well to be cemented successfully. The goals achieved were zonal isolation and elimination of stage tools which had proved to be a weak point in the successful cementing of these wells and the prevention of annular gas and fluid migration.

This paper describes the application of new techniques used to successfully cement two Khuff wells across these critical zones with deep casing strings using single stage cementing.
G-125: An Innovative Hydraulic Drilling Rig For Marginal Fields Development: Field Experience
Authors: Pini Bruno , Marcellini Fabio
Published: December 2007

As far as drilling is concerned, the last years have witnessed the big change, still ongoing, in the availability of innovative technologics that permit to face today's challenge: to be able to provide cost effective solutions for a variety of operating environments.

Challenges are not only those related to extreme scenarios or frontier technologics; there are market niches that normally do not attract the attention from the media but, nevertheless, are very important for the energy industry at large.

On-shore marginal fields exploitation or high risk exploration ventures are two of these niches that drawn the attention of many Oil Companies and led to the decision to design and develop a "fit-for-purpose" drilling rig.

This paper aims at presenting the criteria adopted to design a new rig, called G-125, specifically engineered for marginal fields exploitation and to illustrate the actual results achieved during a twenty-two months long field experience.

Indeed, the rig is actually operating in Italy, in the specific field of application that was designed and built for.
Cementing Through Coiled Tubing Decreases Well Completion And Testing Costs
Authors: Chariag B. , Shaheen M. , Al-Suwaidi A.
Published: December 2007

Conventional applications of cementing through coiled tubing, which has been around over the last decade has now become a standard practice that includes zonal isolation, casing repair, water or gas shut off and zone abandonment. The use of this technique being advantageous both technically and economically, have been extended to include multizone well testing.

This paper describes ADCO experience on how the use of good practices of cement through coiled tubing design and placement helps optimize the overall cost of a well testing operation.
The Effect of Parafos on Drilling Fluids Properties
Authors: Osman Mohammed E. , El-Hardalo Samier M. , AI-Nyadi Thani S.
Published: December 2007

This paper presents an extensive experimental study to investigate the effect of adding Parafos as a corrosion inhibitor on drilling fluid properties. It was found that as the Parafos concentration increases both water loss and mud weight increases and both pH and viscosity decreases. All these properties decrease as temperature increase. It was also found that Parafos is an effective corrosion inhibitor.
Qatar General Petroleum Corporation Multilateral Horizontal Drilling and Completion Experiences
Authors: Mohamed Talib , Shehata Alaa E.
Published: December 2007

Qatar General Petroleum Corporation (QGPC) commenced its multi lateral drilling programme in August 1997 in it's Bul Hanine Field offshore. Seven wells have been completed as dual laterals, four offshore and three onshore. Of the seven, three existing wellbores offshore, were re-entered and converted to dual laterals. One offshore and three onshore wells were drilled as new wells. In all wells, except one, pre-milled windows were strategically positioned in the 9–5/8" casing or 7" liner to allow for drilling the secondary lateral. Some of the key requirements for the techniques used were: the ability to perform selective completions, stimulation, logging and future re-entry in each lateral using coiled tubing. In all cases, the secondary lateral through the window was partially cased and cemented to allow for an open hole completion, to isolate reservoirs, to assist in long term junction integrity and for re-entry after completion. Both single and dual completion strings were utilized. Significant production increases were achieved in comparison to rates prior to sidetracking existing wells and when compared to a single completion in the same reservoir.

This paper reviews the re-entry operations where applicable, drilling, completion and stimulation procedures applied for the dual lateral horizontal wells drilled to date and includes a comprehensive analysis of problems encountered during all phases of the operations. In addition, the economic implications of drilling two horizontal wells versus one dual lateral arc discussed.
Directional Drilling System «ARIADNE» - The Well Path Finder
Authors: Konstantakopoulos I. K. , Stamataki S. K.
Published: December 2007

Directional Drilling System «ARIADNE» is an advanced multi-functional computerized tool aimed to the optimum 3-dimensional well path design and to the real-time control of conventional or more complex types of highly deviated and horizontal wells. Based on effectively designed subsystem algorithms, it can take into account recent technological advances and increased knowledge of reservoir complexity.

System integrated operation is applicable to each part of a drilling process cycle, covering planning, implementation and post-evaluation phase and it can provide: a) sophisticated design of the optimum wellbore geometry of all typical profiles of highly deviated, extended reach and horizontal wells, b) effective positioning of the well within subsurface environment with emphasis to target formation shape, boundaries or areal tolerances, using conventional or advanced geosteering data.

The title reflects system capability to serve petroleum engineers as the Ariadne's clue, in the successful reaching of desired targets through the subground labyrinth, considering drilling objectives, geological or petrophysical features, environmental impacts and technical or economic aspects.
Stimulation of Horizontal Wells in Carbonate Reservoirs
Authors: Aslam Javed , Salat Talib Al
Published: December 2007

The well stimulation techniques currently in use for horizontal wells are generally based on the old technology, developed for vertical wells based on the radial penetration of treatment fluids from the perforations. The geometry of the wells has changed from vertical/deviated to horizontal in the recent years. The difficulties and the costs associated with the stimulation of long horizontal wells is forcing many operating companies to drill under-balance and thus avoid stimulation altogether. The problems of stimulating the long horizontal wells are further compounded by the most selected method of completion i.e. open hole or ‘bare-foot’ because it is almost impossible to control the fluid entry points in the open hole.

Qatar General Petroleum Corporation (QGPC) has employed the conventional stimulation techniques in many horizontal wells e.g. Acid Wash, Foamed Acid, X-Linked acid, and Enzyme Treatment using various jetting tools. The results showed that all the treatments were successful to some extent. However, the cost remained a major issue as the acid volumes are fairly large even at relatively low dosages. In an effort to reduce stimulation costs, QGPC has perused some new. techniques which offer more cost effective well stimulation in comparison to conventional acidization techniques. The new methods are (a) Row-Back Stimulation (b) Reactive Wash (c) use of rotating jetting tools and open-hole perforating. Some of the new techniques have already been applied and some require further refinement and research. The paper covers the case histories and results of the acidization methods used in the carbonate reservoirs. The theoretical aspects of the techniques which require further development are also discussed.
Optimizing Bent Housing Angle in Steerable BHA
Authors: Al Attas Mohamed O.
Published: December 2007

This paper describes the bent housing optimization in Steerable drilling System. The performance of drilling was found as a result of this optimization which was produced from increasing the drilling ROP and reducing the hole profile spiral. Reducing sliding drilling is reflected on drill string while drilling by increasing the torque between drillstring and hole side at high inclination. Since ADMA OPCO used steerable drilling technique the directional drilling became easier to correct the well direction, if required, this correction achieved without any additional trips in presence of surface real time survey reading out. However adjusting and tuning of drillstring bottom hole components (BHA) still requires some optimization such as choosing correct bit, proper motor, right bent housing angle etc. The data used in this study was collected from ADMA OPCO offshore areas mainly while drilling 12 ¼", 8 ½" and 6" holes.
Sour Gas Processing, Disposal, and Utilization as Applied in UAE Reservoirs
Authors: AlFalahy M. A. , Abou Kassem J. H. , Chakma A. , Islam M. R.
Published: December 2007

Both oil and gas reservoirs of the United Arab Emirates (UAE) are known to contain significant amount of sour gas, mainly in the form of hydrogen sulfide. The presence of sour gas poses a difficult problem in terms of production problems, gas processing as well as oil refining. Unfortunately, little is known in the areas of sour gas behavior in the presence of UAE crude. Advances have been done in other areas of unwanted gas disposal and utilization (e.g. Islam and Chakma, Energy Conv. Management, vol. 34, 1993). This paper proposes several solutions to the sour gas problem, complete with numerical simulation and laboratory experiments. The proposed solution deals with both sour gas disposal and oil recovery with sour gas. The problems associated with these techniques are studied in detail in order to depict an accurate picture of the options available.

The sour gas is found to improve the miscibility behavior of the crude oil, the recovery is improved when significant amount of sour gas is present in the injection stream. It is important, however, to differentiate between gas injection under stable and unstable flow conditions. If gas injection is carried out from the top of a reservoir, the flow is likely to be gravity-stabilized. In the presence of an unstable displacement, the gas breakthrough takes place early leading to a decline in the overall productivity.

In order to fulfill the mandate of no-flare by the year 2000, Abu Dhabi oil companies are required to find a no-waste gas separation process. The proposed method solves the problem of gas separation and offers an economically attractive alternative to the current practice of gas flaring.
Bi-Directional Intelligent Pigging of 48 inch Loading Line – Zadco Experience
Authors: Al Amari Jamal , Radhakrishnan R.
Published: December 2007

In this paper we discuss Zadco's experience in carrying out the intelligent pigging of one of it's two 48 inch loading lines using bi-directional intelligent pigging technique with crude oil as the pigging medium. This operation was the first of it's kind in the Middle-East. Intelligent pigging of lines not designed with pig launching and receiving facilities can be a challenge. This is especially so if the lines have never been pigged before, are critical and it is difficult to ascertain the cleanliness of the lines in advance with certainity. The problem is compounded when the lines end sub-sea as in the case of loading lines equipped with floating buoys.

The paper will review the various options considered by Zadco for the inspection of the line considering the fact that the loading lines are not equipped with pig traps.

Discussed are the temporary modifications carried out to enable bi-directional pigging and bi-directional intelligent pigging. Cleaning of the line was carried out using the progressive pigging technique.

Addressed are also the anticipated problems and the steps that had been taken to overcome them were they to occur. The best possible procedure was employed to prevent any sludge from being left behind in the line after cleaning it. Plans were made to dispose of the sludge and solids that would probably be removed from the line and pushed into the oil tanker at the receiving end.

The line cleaning operation and intelligent pigging with ultrasonic inspection tool was successfully completed for loading line-B in Sept-Oct 97 using bi-directional pigging technique.
Reservoir Fluid Identification and Testing with a Modular Formation Tester in an Aging Field
Authors: Ayan C. , Nicolle G.
Published: December 2007

The fluid content of the subzones of an aging offshore carbonate oil field was investigated with a wireline formation tester. Tests were done through a straddle packer module, pumping filtrate into the wellbore till native formation fluids are identified with an optical fluid analyzer module for sampling. The tests were conducted along with observation probe(s) below or above the packer, which recorded pressures to compute horizontal and vertical mobilities. Pressure buildup data from the packer interval were analyzed as "mini-Drill Stem Tests".

Formation fluid contents were identified in ten zones in two wells for completion decisions. The tests in one well indicated that all zones were at residual oil saturation. Mini-DST and packer-probe analysis revealed formation vertical and horizontal mobilities within and across selected zones. These were used to calibrate the anisotropy ratio in the simulation model. Oil sample analysis confirmed saturation pressure and composition of the existing PVT data.
Nuclear Magnetic Logging, Does It Meet Expectations ?
Authors: Boyd D. , El Emam Medhat
Published: December 2007

Nuclear Magnetic Logging was introduced to the industry by Pan Geo Atlas Corp. in 1959. As today, expectations were high. Following an initial period of enthusiasm, interest declined as solutions were not provided. Since then the technology has been periodically reintroduced to the oil industry. The SPWLA Bibliography of NMR Applications"2 records 458 technical references on the subject related to the oil industry. Interest in the technology is understandable considering the prospect of permeability prediction, lithology independent total porosity, effective porosity, wettability determination, hydrocarbon typing, residual oil saturation, and estimate of movable formation water. Today, the newest generation logging tools, CMR* and MRIL+, offer improved signal to noise ratio, faster logging speeds, and superior vertical resolution. The preponderance of recent technical papers highlight the successful application of NMR in clastic reservoirs. Carbonate reservoirs are proving more challenging. Complex pore geometry, varying wettability, intragranular / matrix microporosity, chaotic pore throat / pore size ratios, connected and non-connected vugs, and weak surface relaxivity make interpretation difficult. This paper documents ADMA-OPCO's experience with the CMR in a mixed wet / intermediate wet carbonate reservoir exhibiting high immobile water saturation. CMR total porosity underestimated core / neutron – density – sonic porosity. A T2 cutoff of 280 msec failed to predict the water free oil production obtained. An investigative core analyses program which followed did not provide a unique T2 cutoff, but several, varying from 120 msec to 486 msec. The usefulness of this technology for evaluation of ADMA-OPCO's carbonate reservoirs is judged.
Estimation of In-situ Vertical Permeability Through Matching RFT Data Under Dynamic Conditions
Authors: Hiraoka Takashi , Parker Andrew , Masuzawa Tsutomu
Published: December 2007

An accurate knowledge of vertical permeability (kv) in a thick reservoir is critically important to the design of a successful reservoir sweep development. However, the in-situ vertical permeability is very difficult to ascertain and may not be the same as those measured from core analyses. In this paper the usefulness of understanding ‘abnormal’ RFT data from a producing field is presented, together with a proposed methodology to estimate in-situ vertical permeability through matching RFT data under dynamic conditions.

An ‘abnormal’ vertical pressure gradient (twice the expected value) was detected by RFT within a 140 feet thick limestone reservoir in close proximity to an active producer. Attempts were made to match the data using a fine grid 3D simulation sector model whilst honouring conventional core analysis data (kv/kh ratio of 0.2 to 0.7). It was found impossible to match the gradient with this relatively high kv/kh ratio, even with only the upper perforations on production (indicated by historical PLT logs). Several different assumptions were required to achieve an acceptable pressure distribution match. One case assumed Stylolite layers had very low permeability. In another, uniformly lower vertical permeability for entire layers was necessary. Although a unique solution was not possible, the results strongly suggested that vertical permeability might be lower than previously understood.

Due to the impact of reduced vertical permeability upon future field development, a specialized test to reliably measure in-situ vertical permeability was designed via 3D simulation. The test monitors a pressure wave generated by a partial penetration well at an offset, fully penetrating, well via RFT measurements. The expected pressure responses for such a test are presented.
Obtaining Reservoir Parameters and Flow Profiles From Production-Logging Runs
Authors: Kabir C. S. , Al-Dashti Q. , Kamal D. , Hoadley S. F.
Published: December 2007

Production logging (PL) jobs can be designed so that transient flow tests can be included to maximize information gathering. When downhole pressure and rate data are gathered in a stationary mode, an array of reservoir parameters can be obtained. These parameters include permeability (k), mechanical skin (s), non-Darcy skin coefficient (D), average pressure ( p), and inflow performance relationship (IPR) without the well being shut-in.

We designed and conducted transient flow-after-flow tests to gather downhole pressure-rate data. Pertinent information for PL analysis were implicit in the test procedure involving a single logging trip. Transient flow-after-flow analysis yielded D, p, and IPR by using a recently proposed interpretation technique. In addition, convolution or superposition analysis of the pressure-rate data allowed estimation of k and s. Most of these parameters so obtained were verified by the results of buildup tests conducted on these wells.

This paper also presents a methodology for computing flow rates for a generalized multirate test, leading to improved test interpretation, verification of measured rates and computed parameters, and salvaging tests when a flowmeter lacks the desired sensitivity at low rates.
Case History in Solving ESP Problems in Oil and Water Wells
Authors: A. Abdou Hesham
Published: December 2007

This paper discusses the technical problems encountered in Agiba wells using ESP as an artificial lifting system in both water source wells (WSW) and oil wells, in addition to the applied solutions to overcome these problems.
Towards 2000: ADNOC's Plans for Health, Safety and Environmental Impact Assessments
Authors: Al Mansouri Majid , Brett Robert , Al Tamimi Yusri , Chatter Jack , Rowe Patrick , Smies Maarten
Published: December 2007

Global awareness and concern over Health, Safety and Environment (HSE) has been rapidly increasing all over the world, particularly over the last decade, attention is focussed more often on the oil Industry and its derivative subsets because fossil fuels is used as its main feed stock. The Abu Dhabi National Oil Company (ADNOC) being the leading oil company in the United Arab Emirates (UAE), has adopted an attentive approach to its future Health, Safety and Environmental Management System, whereby it is mandatory now for all new projects to have Health, Safety and Environmental Impact Assessments (HSEIAs) carried out at the four stages (initial engineering design, construction, operation to eventual decommissioning) of the project life cycle. In order to ensure successful implementation of this strategy, it is essential to understand and fully account for the impacts and risks linked to existing operations and approved future expansion plans. To achieve this goal, ADNOC has embarked on an ambitious project to acquire this knowledge by compiling a baseline HSEIA on all of its existing activities and plans by the year 2000. This paper describes the collective way in which the project was launched, the methodology used to undertake the project and the way that ADNOC interacted with its own Group Companies and international HSE Consultant firms to ensure efficient and cost effective implementation of the plan.

This project although in its early stages of implementation, but the lessons learned so far can be applied to other organisations pursuing similar aims.
Utilization of Gas Turbines in LPG PLANT
Authors: Mousa Hatem
Published: December 2007

Abu Dhabi Gas Industries Ltd. (GASCO) operates in its four LPG plants a large fleet of Aeroderivative and Heavy Industrial Gas Turbines as mechanical drivers for Gas Compression and Electric Power Generation packages. GASCO's turbine fleet accounts for 370,000 installed horsepower in addition to 280,000 KW generating capacity.

This paper summarises GASCO's experience which has been gained over 4 Million accumulated run hours under the Gulf environment.
Importance Of The Operator's Involvement In Project Development
Authors: Coupaud Jean-François , Yahya Amer
Published: December 2007

Large projects in the Petroleum Industry are traditionally handled by a dedicated project team reporting to a "Projects Division". For obvious reasons of stability, planning and cost, the Operator's involvement is usually reduced between the issue of the Pre-Project report and the Commissioning or even Start-up of the facilities.
Outcrop-Behind Outcrop Characterization of Thin-bedded Turbidites for Improved Understanding of Analog Reservoirs: New Zealand and Gulf of Mexico
Authors: Slatt R. M. , Browne G. H. , Davis R. J. , Clemenceau G. R. , Colbert J. R. , Young R. A. , Anxionnaz H. , Spang R. J.
Published: December 2007

Well log, well test, and seismic data provide excellent structural and stratigraphic information on subsurface reservoirs, but may not be able to resolve small-scale vertical and lateral attributes which may control oil or gas production. Outcrops can provide this important information provided they are of sufficient areal extent. In this paper, we demonstrate the application of outcrop and behind-outcrop characterization for improved understanding of thin-bedded turbidite reservoirs in the Gulf of Mexico and elsewhere.

A 200m high by 10km long coastal cliff section of the Late Miocene Mt. Messenger Formation, New Zealand consists of 200+ meters of thick-bedded turbidite fan sands and associated thin-bedded fan-fringe sandstone/siltstone, overlain by 300m of thin-bedded slope fan, levee/overbank sandstone/siltstone. This section was characterized at the ‘seismic’ to individual bed scales. Also, 47 and 105m deep holes were drilled behind the cliff face, cored, and logged through the slope fan facies with Fullbore Formation Micro Imager* and Platform Express* logs. A slope-fan model is presented which differentiates proximal levee facies composed mainly of discontinuous, erosionally-truncated Bouma Tb-c beds from distal levee/overbank facies composed of more continuous, thin-bedded strata owing to fewer truncations. An associated channel-fill facies is composed of sandstone/siltstone interbeds which become muddier upward. These three facies exhibit distinctive dip and borehole image patterns.

The model demonstrates the application of outcrop-behind outcrop characterization for improved understanding of thin-bedded turbidites in analog reservoirs. For example, a permeability vs. lithofacies relationship established for the Mt. Messenger strata is common in Gulf of Mexico thin-bedded turbidites. Also, the thin-bedded levee/overbank reservoir facies of the Ram/Powell Field "L sand" in the Gulf of Mexico exhibits very similar features to those observed in outcrop and behind-outcrop cores and logs. Gas production rates of ~100 MMCFD and 9600 BCPD have been achieved from a horizontal well placed in the "L sand" proximal levee facies.

In the broader sense, interactive workstation analyses of lithology, bed thickness, and dip-set groupings seen in the high resolution, behind-outcrop borehole images were used to identify depositional cycles and facies transitions based upon calibration with core and outcrop patterns. The same image analysis methods have been applied to other exploration and production wells in the Gulf of Mexico; one Neogene turbidite example is illustrated.
Adjustable Stabiliser Drilling: A Demanding North Sea Horizontal Case History Success
Authors: Greener M. , Anderson C. , McLellan W. , Hough S.
Published: December 2007

The placement of an adjustable stabiliser in a near bit rotary application is being used with considerable success to drill the extremely demanding horizontal wells in BP's current North Sea Harding Project. High performance horizontal drilling, allied to optimal reservoir performance, is considered paramount to success and specific reference is made to the technical attributes and benefits of utilising the adjustable stabiliser system. Inclination control of the horizontal rotary assemblies is obviously critical with regard to drilling, but it is also proving to be crucial in relation to the holistic total life- cycle management considerations of these very demanding and challenging wells.

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Modeling the Properties of Crude Oil and Gas Systems Using RBF Network
Authors: Elsharkawy Adel M.
Published: December 2007

This paper presents a new technique to model the behavior of crude oil and natural gas systems. The proposed technique is using a radial basis function neural network model (RBFNM). The model predicts oil formation volume factor, solution gas- oil ratio, oil viscosity, saturated oil density, undersaturated oil compressibility, and evolved gas gravity. Input data to the RBFNM are reservoir pressure, temperature, stock tank oil gravity, and separator gas gravity. The model is trained using differential PVT analysis of numerous crude oil samples collected from various oil fields. The proposed RBFNM is tested using PVT properties of other samples that has not been used during the training process. Accuracy of the proposed network model to predict PVT properties crude oils and gas systems is compared to the accuracy of numerous published PVT correlations. The physical behavior of the model is also checked against experimentally measured data for the test samples. The results showed that the RBFNM is reliable and has better accuracy than the conventional PVT correlations. The model can be incorporated in reservoir simulators and can also be used to check the accuracy of future dilferential PVT reports. This study also shows that once this model is properly trained it can be used to cut expenses of frequent sampling and laborious differential PVT tests. The RBFN model can also be used to forecast PVT properties needed for reservoir and production engineering calculations such as material balance, reservoir simulation separator design, and vertical performance design.

P. 35
A Dynamic Model and Simulation for Killing of Empty Hole Blowout
Authors: Jun Fan , Tai-He Shi , Zhang-Gui Lian
Published: December 2007

To kill blowout wells from which all drilling mud has blown out needs some specific knowledge and understanding of how to determine and plan relevant parameters related to a successful killing job. A comprehensive mechanistic model is developed to characterize the cocurrent flow of gas/liquid and dynamic pressure response within borehole, and investigate the complete kill procedures and the necessary conditions leading to a successful kill operation under any given blowout conditions. The model is composed of a set of equations with respect to gas/mud transient flow natures, gas influx and pressure balance relationships.

Based on the theoretical model, a computer program was constituted by solution of the appropriate equations with numerical method, which is currently capable of simulating the complete empty hole blowout process and showing the typical values and results for development and variations of the fluids distribution, flow rate, fluid density and pressure profile along wellbore.

Simulation results indicate that for any given empty hole blowout situations, there is a certain parameter combination region associated with the allowed annular pressure, injection rates and kill mud densities. If the planed kill parameter combination does not fall into such a region, a blowing well is impossible to be killed.

P. 47
Recruitment - The Role of the Headhunter
Authors: Mason B.
Published: December 2007

The purpose of this paper is to examine the growing role executive search and recruitment firms play in the recruitment of human resources, with specific reference given to the oil and gas industry. Growth in the South East Asian oil industry in the early to mid nineties, coupled with the flattening of many organisational structures, created a dearth of management, commercial and technical personnel with suitable skills, knowledge and ability to meet demand on a global basis. It is predicted that the availability of experienced and competent people will continue to fall short of demand, particularly at senior management and executive levels and companies will be forced to recruit key personnel from the international marketplace. Changes to the process and standards adopted by search consultants has led to an increasing acceptance and use of their service. By forming an alliance with large, international consultancies, organisations will gain access to a vast pool of potential employees and will recognise the significant advantages of outsourcing the recruitment function. Changing communications technology, legislation and mobility of personnel as they seek to enhance their competence and attain personal satisfaction, will continue to be significant factors affecting human resource management in the future.
A Multidisciplinary Approach to Characterize the Hu-12 Oilfield, East China
Authors: Chen L. , Niu Y. , Wong P.M. , Wang L.
Published: December 2007

Multidisciplinary reservoir characterization is important to the study of complex onshore fault-block reservoirs in China. Hu-12 fault-block reservoir is a very heterogeneous oil reservoir with high water-cut. The major problem for the Hu-l2 development was the use of imprecise geological models provided by qualitative methods, which could not handle the heterogeneities in a quantitative manner. This study employed an integrated reservoir characterization approach to reconstruct the geological models for the above reservoir and to provide further development options. The case study uses a multidisciplinary knowledge from geology, geochemistry, well logging, reservoir engineering and computational intelligence to combine static and dynamic characterization. The final product of the above integrated study is the distributing patterns of remaining oil in the Hu-l2 Oilfield. Further drilling prospects are provided to extract the remaining oil in the potential areas.

P. 91
Difficult Drilling Requires Faster Learning - A Case Study
Authors: Wilson C.A. , James C.M.
Published: December 2007

This paper describes the processes involved in the developing of a learning culture, and implementing organizational learning software as a pilot project. The chosen location for the pilot project was Chevron Niugini's Drilling Department at the Iagifu Ridge Camp in the Southern Highlands of Papua New Guinea. The Pilot was part of a larger joint effort by Mobil, BP, Texaco and Chevron (MoBPTeCh) to understand how to more effectively capture and share experience in well operations.

Over a period of six months, Organizational Learning System software was customized to suit the unique drilling operations in Papua New Guinea. To accommodate the system, a cultural change, relative to "learning", was proposed for the office and the rigsite personnel. It was necessary that the ownership of becoming a learning organization was accepted by all personnel involved. The rigsite is the initial location where an organization will determine if the well plan requires modification. The real- time rigsite understanding, verification and assurance of the plan changes is the driver for continued learning. Subsequently, incorporating lessons into future well planning is essential for anticipated improvement. Both of these actions have been crucial to the success of the implementation of the system. All changes and decisions are documented in the Organizational Learning System, with future well plans, created in the office, reflecting these documented alterations.

This paper examines the keys to obtaining a learning culture both in the office and at the rigsite, as well as highlighting other benefits obtained by implementing the Organizational Learning System software at Chevron Niugmi.

P. 101
Monobores - Making a Difference to the Life Cycle Cost of a Development
Authors: Macfarlane M. S. , Mackey P. A.
Published: December 2007

Monobore completions offer significant full-life cycle cost savings for the future development of the Cooper Basin in Australia. In May 1997 Santos Ltd., established a multidisciplinary Monobore Review Team comprising Reservoir, Drilling and Geoscience personnel to: Review the South Australian Cooper Basin monobore population to identify issues that could promote the wider use of monobores for optimising gas development.Identify cost savings associated with the adoption of monobores as the ‘standard’ wellbore design.Define the Ideal Monobore and the minimum Wellbore (Integrity) requirements.

This paper describes the results of the Review Team’s work. It covers the paradigm shift required to implement monobores as a ‘standard’ wellbore design, the initial operational problems encountered, the cost savings realised and some of the "Blue Sky" potential that monobores offer.