bluuebunny/crossref_metadata_2025 huggingface dataset:
Cost Effective Modular Unit for Cleaning Oil and Gas Field Waste Water
Authors: Zinberg M. B. , Nenasheva M. N. , Gafarov N. A.
Published: December 2007

Problems of enviromental control involving conservation of water resources are vital for the development of giant oil and gas condensate fields near Caspian Sea (Russia) characterized by water shortages.

One of the urgent tasks of oil production industry is to use all field waste water consisting of underground, processing and rain water. It was necessary to construct a new highly effective equipment which could be used in local waste water treatment.

Now we have at our disposal a technology and equipment to meet the requirements to the treated water quality. Thus we have installed a modular unit of 100 m3/a day capacity to clean waste water from oil products, suspended matter and other organic pollutants at Orenburg oil and gas condensate field, Russia. The unit provides with a full treatment of produced water and comprises a settling tank with adhesive facility, the number of sorption filters, Trofactor bioreactors and a disinfecting facility. The equipment is fitted into three boxes measuring 9x3.2x2.7 m each. The equipment is simple in design that enables to save money, time and space. Sorption filters, bioreactors as well as the Trofactor process are a part of know-how.
Ecologically Safe Method to Monitor Fluid Filtration in Oil and Gas Bearing Formations and Wells
Authors: Zinberg M. B. , Ivanovskaya I. B. , Mezhebovskaya G. P. , Gafarov N. A.
Published: December 2007

Effective production of oil, gas condensate and natural gas depends on the geological structure of oil and gas bearing formation. Having analyzed gas saturated reservoirs of oil and gas bearing formation in Orenburg oil and gas condensate Held, it was concluded that the wells in the sites of high vertical and horizontal fracturing are flooded by underground waters. Direct data and field take-off arc used to determine the reservoir direction, its filtration and capacity characteristics.

Today there are some methods to monitor the direction of stratum fluid movement using radioisotope or sound waves though their application is limited. A radioisotope method is not ecologically safe, others demand a complicated equipment and specially trained personnel.

We have developed and model-tested a biological tracing method to expose the zones of increased fracturing and of vertical and horizontal communication between wells and strata-reservoirs. The method is especially effective for sulfated carbonate reservoirs of heterogeneous fracturing.
Disposal of Nonhazardous Oil Field Wastes into Salt Caverns
Authors: Veil John , Elcock Deborah , Raivel Mary , Caudle Dan , Ayers Robert C. , Grunewald Ben
Published: December 2007

Bedded and doma! salt deposits occur in many states. If salt deposits are thick enough, salt caverns can be formed through solution mining. These caverns are created either incidentally as a result of salt recovery or intentionally to create an underground chamber that can be used for storing hydrocarbon products or disposing of wastes. This paper evaluates the legality, feasibility', and suitability of disposing of nonhazardous oil and gas exploration, development, and production wastes (hereafter referred to as oil field wastes, unless otherwise noted) in salt caverns.

In 1988, the U.S. Environmental Protection Agency (EPA) published a list of those oil field wastes that were exempt from regulation as hazardous wastes under Subtitle C of the Resource Conservation and Recovery Act (RCRA). EPA's Underground Injection Control (UIC) regulations allow most of those oil field wastes to be injected into Class II UIC wells. At the state level, only the Railroad Commission of Texas (TRC) has formally authorized disposal of oil field w astes into salt caverns, although several other states are considering authorizing the practice. The TRC has issued permits for six facilities, but as of May 1995 only three of these were active. In August 1995, the TRC released draft proposed amendments to TRC Rule 9, the regulation that governs underground injection activities in Texas. There are no outright regulatory prohibitions on the use of salt caverns for disposal of oil field wastes at either the federal level or in the eleven states contacted as pan of the study.

The types of oil field wastes that are planned for disposal in salt caverns are those that are most troublesome to dispose of through regular Class II injection wells because they contain excessive levels of solids (i.e., used drilling fluids, drill cuttings, completion and stimulation waste, produced sand, tank bottoms, and soil contaminated by crude oil or produced water.)
Sustaining Global Progress - in Partnership with the Environment
Authors: Smith A. L.
Published: December 2007

A sustainable development strategy for Marine Fabrication and Decommissioning facilities has been developed and implemented, with the application of environmental pro-grammes; by understanding the effect of the facilities operations on the ecosystem and through minimising the environmental impacts on SSSI/SPA/SAC/Ramsar/Natura 2000 sites in a scientifically based, cost effective manner. This paper provides an international perspective for all E & P operations, especially those in the sensitive inter-tidal zone.
Well Testing - Oil Disposal Options
Authors: MacFarlane Timothy
Published: December 2007

This paper discusses and contrasts the use of clean-burning equipment used for flaring with the use of a well-test vessel that captures the hydrocarbon products for sale rather than disposal. Even though new burner technology eliminates much of the black smoke and hydrocarbon fallout, burning is prohibited in some environmentally sensitive areas. Under these circumstances, a properly equipped well-test vessel could be used to capture products for sale. The technology chosen is usually decided based on the technical parameters of the well being tested.

New burners and well-test vessels both represent the "best available technology" (BAT) to minimize environmental impact. Therefore, case histories demonstrating the use of clean burning and the use of a well-test vessel are presented. Technology detailed in this paper further demonstrates how the industry can contribute to improved environmental protection in the North Sea.
The Troll HSE Risk Management System
Authors: Wiig Erik , Berthelsen Inge , Donovan Kevin
Published: December 2007

The Petroleum Act and Internal Control regulations in Norway lay down requirements for how HSE shall be managed and documented. To comply with the Norwegian legislation the Troll Project has developed an HSE Risk Management System (RMS) structured around Hazards and Effects Management. The resulting quality, technical and operating integrity, and HSE performance are an endorsement of the power of RMS.
Two-Screw Multiphase Pump Behavior In Heavy Crude Oil
Authors: Gonzalez R.
Published: December 2007

Multiphase fluid handling technology has been applied worldwide in its commercial version since 1984, specializing in pumping medium and light crude oil and its associated gas. This technology was applied to Venezuela's heavy/extra-heavy crude oils in 1995 in a field evaluation in Corpoven's Arecuna Field, Hamaca Area in the Orinoco Belt. This was done by installing a multiphase pump with a capacity of 53.5 MSTBD equivalent (5.5 MSTBD of liquid and 48 MSTBD equivalent of gas), an intake pressure of 30 psi, and a maximum discharge pressure of 700 psi (a pressure differential of 670 psi). This equipment was designed to handle the production associated with eight wells, located 5.28 miles from the nearest crude oil separation and treatment facilities.

After 3260 hours of continuous operation, the results obtained from the evaluation of the two-screw multiphase pump show normal behavior, handling a flow of 52 MSTBD equivalent (11 MSTBD of liquid and 41 MSTBD equivalent of gas), an intake pressure of 20 psi, and a discharge pressure of 300 psi (a pressure differential of 280 psi). The average power consumption was 400 kw/hr. Results empowered Corpoven to include multiphase technology as a component of its existing new developments. Multiphase pump low pressure intakes have resulted in lower pressures at well heads (from 140 psi to an average of 80 psi), allowing a 12.5% production increase, equivalent to 220 STBD.

The purpose of this paper is to reveal the results obtained from a field evaluation of a multiphase pump application in Venezuelan heavy/extra-heavy crude oil production areas. Additionally, this paper includes an economic analysis of multiphase versus conventional gathering facilities and operating recommendations based on a commercial pilot test.

Introduction

Corpoven's heavy/extra-heavy crude oil production has traditionally been handled and transported through a flow station-production station arrangement, where produced fluids are collected, separated, measured, and subsequently treated and transported to different destinations (compressor plants for gas and tank farms for crude oil). This conventional scheme has worked efficiently when the processes are continuously optimized, however, the costs of installations and major equipment have increased considerably, in addition to the operational inconveniences represented by the presence of crude oil storage sites scattered around the producing areas. In order to take advantage of new technologies that add value to processes of gathering, handling and transportation of produced fluids to the production stations, and reduced investment and operating costs, beginning in 1995 Corpoven has began to apply multiphase pumping technology on heavy/extra-heavy crude oil production in the Arecuna field within the Orinoco Belt.

P. 103
Implementation of a Risk Analysis Method on Fishing Operations Decisions
Authors: Cunha J.C.S. , D'Almeida Albino L.
Published: December 2007

It is very important to determine the economical feasibility of a fishing operation in order to know whether to continue or interrupt the fishing procedure. This decision, when erroneously taken, can often lead to unexpected losses of money and time.

In the past the decisions concerning whether to continue or interrupt a fishing operation were based primarily on the operator's previous experience. This procedure often led to wrong decisions and consequently unnecessary monetary losses.

This paper describes the implementation of a decision-making method based on risk analysis theory and previous operation results from the field under study. The method leads to more accurate decisions on a daily basis allowing the operator to verify each day of the operation if the decision being carried out is the one with the highest probability to conduct to the best economical result.

Introduction

Fishing problems can occur during drilling, completion or production operations in oil and gas wells. These costly and undesirable remedial operations have been resulting in annual losses of US$ 500 million worldwide.

Recently a decision-making method to deal with this problem was developed. Based on risk analysis theory, probability distribution and previous operation results, the method conducts to more accurate decisions allowing the operator to verify if the decision being carried out is the one with the highest probability to conduct to the best economical result.

Theoretical Review

In Ref. 1, the basic concepts of the method were presented. Also derivations of all equations were presented and thoroughly discussed. Following, a review of the mainly concepts and equations.–Economic fishing time (EFT): EFT represents, at a certain moment of the operation, the amount of time within the operation should be concluded in order to produce a satisfactory economic outcome.(1)–Probability of Success: This is the probability that the operation presents to be successfully concluded within the EFT.(2)–Expected cost of the operation: Value calculated using the principles of risk analysis theory. It involves not only the costs but also the operation probabilities of success and failure at a certain moment.(3)–Conditional probability of success at day i of the EFT:(4)–Conditional probability of failure at day i of the EFT:(5)

P. 283
Optically Derived Numerical Descriptors for Classification of Carbonate Rock Fabrics
Authors: Conley C.D. , Davis J.C.
Published: December 2007

Carbonate rocks, although relatively simple in their basic mineralogy, present a bewildering array of constituents, textures, structures, and diagenetic features, as well as complex pore geometry. For these reasons, detailed quantitative studies of carbonate rocks require a large investment of time on the part of the carbonate petrologist simply for the purpose of data gathering. Conversely, purpose of data gathering. Conversely, if large numbers of samples are to be studied or if time and cost are important factors, relatively little information is extracted from the available samples.

Derivation of petrographic data from carbonate rocks may be considered a problem of image analysis. One approach to such problems is to utilize techniques and algorithms developed in the field of pattern recognition. Identification of rock components and characterization of rock fabric basically involve signature analysis and pattern interpretation. In addition to the characterization of rock constituents, it is equally important to define the nature and distribution of rock pore systems, which may be at least as complex as grain fabrics.

It is possible to identify individual constituents of carbonate rocks, such as biotic constituents, by a multispectral process. with this procedure, the reaction process. with this procedure, the reaction of different phases to staining agents, differences in surface texture, crystal fabric, and other "differences in appearance" are combined to achieve unique spectral signatures for each class of constituents. Presently available equipment, originally Presently available equipment, originally designed for analysis of multispectral radar and light imagery from satellites, can classify ten different constituents identified by up to five different spectral characteristics. Once rock constituents have been properly identified, individual particles can be counted, their areas particles can be counted, their areas computed, and statistical measures derived from the image. Equipment can be computer-interfaced for immediate data reduction and display.
Optimum Acid Volume Estimation Using Real-Time Skin Evaluation
Authors: Boonyapaluk P. , Hareland G.
Published: December 2007

During matrix acidizing stimulation jobs, the use of more acid does not mean more skin reduction during the treatment. The excessive acid volume serves only to dissolve and weaken the matrix rather than remove the damage. The optimum amount of acid needs to be determined in each matrix stimulation case. This is done by calculating the real time skin value which is used to estimate the optimum volume needed.

The acid volume and type used in matrix acidizing stimulation is usually based on the experience of the operator in the field. Trial-and-error or on-site injectivity measurements are used to optimize the acid volume. In order to limit trial-and-error exercises, a real-time on-site treatment evaluation method has been developed to assist the field engineer with a new real-time matrix volume estimation technique. History matching and curve fitting the early stages of the acidizing job, the method determines when the maximum damage removal is obtained and corresponding acid volume.

This work proposes the use of real-time matrix acidizing data in conjunction with real-time skin effect calculations to estimate the optimum acid volume to be used on-site. The results are compared with three acidizing field cases in the paper, but has been verified for sixteen (16) field cases. The method can be used for optimizing acid volume during matrix stimulation in progress and deciding when to stop pumping the acid.

Introduction

The concept of skin effect has been used as a magnitude of near wellbore flow impairment. The total skin effect is a multi-component quantity including mechanical skin effects such as mud solid and filtrate invasion during drilling and cementing, formation debris during perforation, and fine migration during production. Actually, the skin effect accounts for any deviation from an ideal undamaged, open-hole, vertical well. "Damage" may be caused by a number of phenomena on which traditional acidizing has no effect. Some of these pseudo-damage phenomena are gravel-pack and partial perforation and penetration.

Matrix acidizing stimulation is a treatment intended to remove near-wellbore damage. The determination whether to and how much to stimulate a well and the type of acid treatment should depend on comprehensive pre, real-time, and/or post analysis with high emphasis on quality data gathering. Matrix acidizing job effectiveness can be assessed through real-time or post treatment evaluation of data collected during the acid treatment.

During the matrix acidizing treatment, fluids are injected into the well, causing a pressure response recorded at the wellhead.

P. 381
Lease Operatorships and Farmouts: Changing the Oil Production Scenario in Trinidad's Land-Based Fields
Authors: Hosein Aleem
Published: December 2007

The history of the oil industry in Trinidad's land-based fields, reflects a domination by foreign multinationals initially, followed with ownership by various state-owned oil companies. Recently however, local entrepreneurs have been afforded the opportunity to participate to some extent, in oil production activities of the land-based operations of the state-owned oil company.

The state-owned oil company of Trinidad and Tobago has over five thousand (5000) inactive wells. Because of limited capital resources and the resultant low priority for reactivation, a programme of leasing blocks of these idle wells to small independent operators was initiated in July 1989. This programme is currently being expanded because of its initial success. In addition, acreages are being offered for farmout operations, again because of the scarcity of capital funds for internal investment and the associated risks involved.

As a consequence of these programmes, the oil production scenario in Trinidad's land-based operations is undergoing a radical transformation. This paper reviews the current status of lease operatorships and farmouts and discusses the key issues involved.

Introduction

Trinidad is the most southerly of the Caribbean Islands and is located to the east of Venezuela (Figure 1). The major part of the history of the oil industry of Trinidad's land-based operations reflects a domination by foreign multinationals including Shell, Texaco and British Petroleum amongst other smaller foreign companies. Over the years, the land-based assets of these companies were acquired by the Government of Trinidad and Tobago to form two state-owned oil companies TRINTOC and TRINTOPEC. In 1993, these two companies were eventually merged into one state-owned oil company, PETROTRIN.

In the late 1980's, because of the low oil prices, many wells became uneconomic to produce and were left idle.
Impact of Foamy Oil Mechanism on the Hamaca Oil Reserves, Orinoco Belt-Venezuela
Authors: de Mirabal M. , Gordillo R. , Rojas G. , Rodriguez H. , Huerta M.
Published: December 2007

This paper summarizes an integrated field, experiments and computer simulation research program conducted to support a review of the reserves and development plan for the Hamaca Area in the Orinoco Belt (OB), Venezuela. The impact of the foamy oil mechanism on the Hamaca heavy-extra heavy Oil reserves and the importance of understanding this behavior is presented in this paper. The study was conducted in reservoirs with the largest production history (within the OB). The experimental results showed in-situ formation of non-aqueous oil foam with high gas retention, improving oil mobility and leading, therefore, to high well productivity. An experimental recovery factor over 10% was obtained under primary conditions so it was possible to increase oil reserves by approximately 30% over the currently accepted volumes. Experimental results provided input parameters to perform preliminary simulation runs which would allow the modification of well spacing schemes, the generation of a high-probability production profile, and the optimization of artificial lift systems, incorporating larger capacity equipment.

Introduction

When the exploitation of Hamaca heavy oil reservoirs began, it was assumed that the primary production mechanisms were sand compaction, solution gas drive and thermal effects due to steam cyclic stimulation which improves oil mobility. However, an unexpectedly high cold production lead to research of the drive mechanisms to explain the special production performance. Similar behavior has been observed in the Lloydminster area of Canada. Despite considerable speculation, a number of authors have studied foamy oil behavior and some research has recently been done, yet the mechanism leading to this behavior still remains to be successfully explained. Reservoir properties that were proposed to explain the behavior in the OB and in Canada include unusually high sand permeability and/or critical gas saturation. In Canada, high critical gas saturation is now an accepted property of some reservoirs, the so called Foamy Oil reservoirs. However, a monitoring field program of sand compaction and land subsidence did not show any evidence that this mechanism has taken place in the Hamaca Area. None of these proposed properties and mechanisms are consistent with field observations. On the other hand, numerical models showed high uncertainty when trying to match the reservoir production pressure behavior. As a consequence, a research program was designed as part of an integrated reservoir study. It included a production behavior analysis, an experimental program for fluid/porous media characterization through conventional and nonconventional PVT tests, and solution gas drive experiments at research centers of Venezuela (INTEVEP), Canada (PRI-CMG) and USA (LAB).

P. 639
Simulation of Injection Water Supply Wells in Central Arabia
Authors: Nasr-El-Din H. A. , Rosser H. R. , Hopkins J. A.
Published: December 2007

Seventeen wells were drilled in an aquifer to supply water for injection in an oil field in central Saudi Arabia. Although these wells produced high volumes of clear water on initial completion, during field start-up most wells produced poor quality water, and only at much reduced rates. A stimulation program to restore the productivity of water supply wells was initiated. The program included injection of 15 wt% HCl along with a friction reducer and a corrosion inhibitor. Samples of all injected and produced fluids were collected to analyze the solid particles present in the samples, and measure the concentration of key ions in the acid returns. The results of these analyses have been used to determine the mechanism by which damage to the wells occurred.

In this paper we present conclusive evidence, drawn from analyses of the returned acid cleaning fluids, which indicates that biomass and microbial corrosion products, produced by active sulfate-reducing bacteria (SRB) populations during shut-in periods, were responsible for much of the damage experienced by these wells. The investigation has highlighted an absolute requirement for an effective downhole SRB control program to prevent subsequent damage to water supply wells which have been restored by the cleaning program.

Based on the results of this investigation, an optimized cleaning procedure which will restore water productivity, and at the same time will minimize casing corrosion, has been developed. This program includes acid additives to minimize precipitation of calcium sulfate, elemental sulfur and ferric hydroxide, which can damage the formation and reduce the productivity of water supply wells.
Cost Benefits Derived from the Implementation of a Corrosion Management System
Authors: Attwood P. A. , Bool K. K. , Van Gelder K.
Published: December 2007

In order to combat the rising costs attributed to corrosion in PDO's oil production operations, an initiative was undertaken to develop a Corrosion Management System. A description is given of the functionality of the developed system, Pacer-CM, which has been designed to capture all monitored data deemed relevant to corrosion control for all facilities exposed to a corrosion risk. The financial benefits that have been accrued in the relatively short time frame that the system has been operational are also discussed.
Fluviatille Reservoir Modelling – Integration of Geological, Seismic and Production Data with Stochastic Modelling Techniques for Reservoir Management Optimisation
Authors: Silva A. Costa e , Silva F. P. , Soares A. , Weber K. J.
Published: December 2007

Fluvial sandstones are important hydrocarbon reservoirs in the Middle East and world-wide. However the significant lithological heterogeneities and lateral continuity are main limitations when considering reservoir development plans. Furthermore low net-to-gross sequences are usually beyond seismic resolution as only the stacked sandstones of the incised valley fills provide sufficient acoustic contrast to be recognised seismically. Major problems are usually encountered in defining sand volume, connectivity and recoverable hydrocarbons. All these factors are critical when considering field management plans and are related directly with the definition of complex spatial configurations, constrained to geological information usually via a genetic classification scheme.

When insufficient information is available the optimisation of modelling procedures becomes of utmost importance. In those cases the integration of all the available information with stochastic modelling techniques minimises uncertainties in the input values used as reservoir parameters for building predictive models for the distribution of sandbodies, flow properties and recoverable hydrocarbons.

This study concerns the development of an integrated methodology for modelling fluvial sequences presenting low net-to-gross ratios, in which channel belts are enclosed within flood plain fines. The main steps are: i) characterisation of channel main morphological features from well data and outcrop analysis; ii) stochastic simulation of channels geometry conditioned to local anisotropy of meander orientations (dipmeter measures, FMI/FMS, etc.); iii) pos-processing of the stochastic images of the meander-belt structures using a morphological filter to clean noisy features.

An example from the Middle East is presented in order to illustrate the application of the methodology to a typical fluvial environment presenting complex characteristics.
Developments in Multiphase Metering
Authors: Ribeiro Alvaro
Published: December 2007

In this paper we will present new techniques for measuring three phase flow using the following approaches:

– Homogenisation – In line separation, metering and recombination – In line metering; leave as it is

Within the concept of "In line metering; leave as it is" the use of the Multi Capacitance technique or the Combination of dissimilar flow sensors and energy absorption probes, are with some limitations in a fast track to be considered proven technologies.

Latest field test results of the Multi Capacitance technique will be presented.
Fault Interpretation and Fracture Morphology: A Case Study of Jurassic Carbonate Reservoir in El-Bunduq Oil Field, Offshore Abu Dhabi and Qatar
Authors: Honda Nobuyuki , Mohamed Kamel Mahmood Abouelenein , Loader Chris , Akbar Mahmood
Published: December 2007

A simple salt dome and a few sets of graben faults characterize the structure of the El Bunduq Oil Field, where the Jurassic carbonates comprise the main reservoirs. The understanding of faults and fractures deepened after the 3D seismic survey and the drilling of a horizontal well in 1994-1995. The present study principally deals with the fault geometry mainly based on 3D seismic and the properties of fractures based on borehole image logs. Discussions shall be further extended to sealingness of fault planes, relationship between faults and fractures, and a role of fractures in the drainage systems of hydrocarbons.
Effect of Inorganic Gases on Reservoir Quality, Abu Dhabi Onshore Structures
Authors: Ayoub Mohamed R. , EnNadi Ibrahim M. , Abdulla Azhari A.
Published: December 2007

Some Palaeozoic (Permian) and Mesozoic reservoirs of Abu Dhabi contain variable amounts of inorganic gases, namely hydrogen sulphide, carbon dioxide, and nitrogen. The vertical and horizontal distribution of these gases vary considerably owing to various factors such as the proximity to the source area, hydrocarbon and other basinal fluids migration pathways, burial depth, variation in geothermal gradient, and in the case of hydrogen sulphide, the presence of anhydrite. The inorganic gas concentrations together with the impact of their existence on reservoir quality are discussed in this paper.

Integrated petrographic and gas data analyses indicate a proportional relationship between secondary calcite cementation and hydrogen sulphide concentration. Calcite generated as a by-product of the thermo-chemical reaction between anhydrite (CaSO4) and organic gases mainly methane (CH4), played a significant role in damaging the porosity in the studied reservoirs. A direct effect of this phenomenon is witnessed in the Khuff Formation in Abu Dhabi (Worden et al., 1995). This process probably contributed to the marked deterioration of reservoir quality in some of the Thamama zones at NE Bab field. Calcite rich basinal fluids, originated in the Falaaha trough and generated from the thermo-chemical reaction of methane and anhydrite, migrated laterally through the Asab Oolite and then vertically into the Lower Cretaceous reservoirs. This process, among others, has contributed to the deterioration of the petrophysical characteristics of these reservoirs.

Carbon dioxide, which is dissolvative, in formation water, created a weak acid that provided additional microporosity. In the Habshan Formation, the CO2 content increases with depth and as a consequence, the porosity in these reservoirs was enhanced due to leaching caused by the dissolved carbon dioxide.
Integration of 3D Seismic Data Into Reservoir Models Using Geostatistics
Authors: Silva A. Costa , Guerreiro L. , Maciel C. , Ramos L. , Guerra R. , Soares A.
Published: December 2007

In complex oil reservoir a detailed characterisation of lateral variations of lithologies and reservoir properties is essential to optimise field development plans and maximise effective recovery of in-place hydrocarbons.

This paper illustrates how a flexible and multidisciplinary methodology can integrate 3D seismic data with geological and petrophysical information in order to enhance the identification of lithologies, quantify bed thickness, perform vertical zonation, establish the continuity and extend of reservoir zones and predict inter-well properties. 3D Seismic data (amplitudes, interval travel times between events, frequency variations, etc.) are correlated with porosity, fluid type, lithologies and net-pay thickness via the use of geostatistical models. A methodology of stochastic simulation is proposed in order to integrate 3D seismic data (amplitudes) and well data (rock-types) through a multisteps conditioning approach. This approach is as follows:

♦ In each grid node, local conditional probability distribution functions are derived from the global calibrated regressions between seismic amplitudes (RMS-Response Phase Map) and well petrophysical properties. A probability field simulation of primary variables is performed, based on these cumulative probability density functions (cpdf). ♦ In a second step the simulation is conditioned to the well data petrophysical values.
3D Survey Design, Acquisition, and Processing for Reservoir Characterization and Monitoring
Authors: Lansley R. Malcolm , Fleming Mike , King Geoffrey A. , Will Bob
Published: December 2007

In the early days of 3D seismic, there was a common tendency to classify the objectives of any survey as being either "structural" or "stratigraphic". The parameters selected for the survey design and data acquisition, and those selected for the subsequent data processing, would often change depending upon the classification. If we look at the interpretation of most 3D surveys we can see that this simple classification is not justified. More and more information is extracted from every data set, and then used to improve our understanding of the reservoir. Most 3D surveys collected today are, to a greater or lesser extent, being used as important components in reservoir characterization studies. The objectives of such studies being the integrated understanding of the reservoir's structure, the lithology, and the pore fluids.

Although significant time and effort is usually spent trying to achieve the optimum technical design for these 3D surveys, there are always compromises because of cost, time and other influences such as environmental impact. The technology available for recording and processing seismic data in a cost effective and timely manner often results in limitations in the results which are provided to the interpreter. It is important for the interpreter to understand the nature and relative importance of these limitations. In recent years, an increasing number of time lapse (4D) seismic surveys have been acquired. In these cases the seismic data is the subject of additional objectives i.e. the monitoring of fluid movements through the reservoir and the subsequent use of this information to update the reservoir simulation model. These reservoir monitoring studies present some additional requirements on both acquisition and data processing systems, if the studies are to be successful.

This paper discusses some of the data acquisition and data processing issues which must be considered when acquiring seismic surveys for reservoir characterization and monitoring.
Applications of a New Production Logging Tool to Locate Fluid Entries and Borehole Flow Imaging
Authors: Boyle Keith , Bustani Aresh
Published: December 2007

Production Logging examples including a new sensor which provides four independent water holdup measurements are presented. Combined with the conventional Production Logging string, the Floview(†) Tool, significantly improves downhole flow diagnosis in vertical and deviated wells. Fluid images from four symmetrically positioned probes provide information on flow regimes and phase segregation. The tool has specific applications in horizontal wells for water holdup determination in segregated flow conditions.

The examples provided present surveys from five wells conducted in one of the Middle East reservoirs, where the objectives were not only to identify the main water and gas entry zones into the wellbore, but also to determine the quantitative downhole flow profile.
The Ultimate Line Drive Using Multilateral Wells: Plans for 200 km of Horizontal Hole in the Saih Rawl Shuaiba Reservoir, PDO
Authors: Seeberger F. C. , Rothenhoefer H. W. , Akinmoladun O. J.
Published: December 2007

The Shuaiba Formation at Saih Rawl, a tight carbonate reservoir in Central Oman, was not fully exploited after discovery for over 20 years with only three vertical wells producing at marginal rates. Exclusive use of horizontal and multilateral well technology has given the field a new life resulting in immediate full field development. A well lay out was chosen to accomplish an ideal line drive. This waterflood project involves the injection of produced water through multilateral horizontal injectors to provide pressure support. Two or three parallel legs are placed below the OWC to achieve bottom water sweep. The oil is produced through single or dual horizontal wells drilled along top reservoir equally spaced between the injectors at a maximum oil column height of 32 m. The wells are drilled at a spacing of 125 m lateral and some 30 m vertical distance between producers and injectors. Individual laterals are more than 2 km long. As a result of this development plan ultimate recovery is expected to rise tenfold from 3.9 (depletion only) to 39 min m3.
Pilot Gas Injection Design in Two Middle East Carbonate Reservoirs
Authors: Dabbouk C. , Namba T. , A-Alim Mohammed S.
Published: December 2007

This paper presents a pilot gas injection design in two massive carbonate reservoirs in one of the middle east fields. The eastern part of the field, where both reservoirs depict good reservoir characteristics, has been developed by the application of five-spot water injection patterns. However, in the western part of the field which is under primary development, a sharp decline in reservoir characteristics isnoted. Anunexpected water breakthrough occurred in the eastern part while production from the western part is declining due to lack of pressure support. Under these situations, a decision was taken to assess the effectiveness of gas injection in enhancing the oil recovery and providing pressure support. This paper is focused on the pre-pilot investigation, selection of pilot areas, laboratory experiments (solubility and swelling tests, slimtube and coreflood experiments), development of Equation of State (EOS), compositional sector model studies and the monitoring programme.
Horizontal Drilling Performance Analysis
Authors: Al Attas M.O.
Published: December 2007

Horizontal Drilling Performance Analysis.

Abu Dhabi Marine Operating Company (ADMA-OPCO) drilled its first horizontal well in 1989 in Abu Dhabi offshore area in the Arabian Gulf. Since then ADMA-OPCO has gone along way. By 1995 over 100 horizontal wells have been drilled using different techniques.

Introduction

As time passes and more experience was gained, the more drilling performance had improved. This is clearly indicated by the drilling rate of penetration (ROP) which will be highlighted in this paper. ROP is one of the main tool used to measure performance but it is not the only factor. Others such optimization of bottom hole assembly (BHA), mud and milling fluid stimulant acid and introducing new equipment are used as measuring tools for the performance. The content of this paper is based on a number of studies conducted by ADMA-OPCO for the last seven years. It aims to highlight the major factors affecting th performance means of measurement.

WELL TYPES

There are two types of horizontal wells that are necessary for the development of offshore area oil fields namely:Producing wellsInjecting wells

Data for both types have been used to support the results high lighted by this paper.

There are various techniques used in drilling horizontal wells. The scope of this paper is to cover the main techniques used by ADMA-OPCO and in particularly those which have an impact on drilling performance. The various techniques covered here in, are as follows:Medium radius curvature.Short radius curvature.Open a window in 9 5/8" casing (re-entry wells).Milling 7" liner (re-entry wells).Drilling single, dual and multi lateral drains.

The following are the subject means for measuring drilling performance:

1. ROP

The good ROP was achieved by combination of optimizing of drilling equipment parameters, drilling fluid and introducing new drilling equipment.

2. DRILLING COST

This was achieved by either having good drilling ROP or reducing the well's expenditure by eliminating some used equipment.

P. 838
Multi-Lateral Horizontal Drilling Problems & Solutions Experienced Offshore Abu Dhabi
Authors: Ismail Gamal , El-Khatib H.
Published: December 2007

ZADCO's Offshore oil field which is a stacked reservoir system was considered as one of the optimum candidates for horizontal drilling applications. The flourishing of horizontal drilling technology has completely changed the development strategy criteria of the reservoirs.

In early 1989, horizontal drilling was experimented in ZADCO's Offshore field, which became an essential part of the new reservoir development program. Eighty five horizontal wells were successfully drilled and completed.

A rapid development in horizontal profile was achieved in ZADCO's Offshore field using the latest horizontal drilling technology to drill complex Multilateral horizontal wells: Multilateral in different directions from parent well bore, Multilateral with two branches in one thin reservoir, Multilateral with Stair-step/traverse trajectories to minimize drilling through tight barriers and to delay water breakthrough.

Several problems were encountered while planning, drilling, completing & stimulating the complex multilateral horizontal wells such as:

Maintaining zonal isolation among the various reservoirs.

Minimizing the drilled footage through tight barriers/poor facies, to control sweep efficiency and to delay water breakthrough by drilling stair step or traverse hole trajectory

Anchor-stock utilization.

Drilling multilateral horizontal wells with low departure target.

The development of thin & tight oil reservoir

Minimizing casing cement bond failure by drilling multilateral holes from one window.

Target centralization within multilateral sections in different directions

Stimulation of multilateral barefoot completion.

The paper will focus on the solutions of above problems experienced in the multilateral horizontal wells implemented in the field offshore Abu-Dhabi.

Introduction

This field, which is one of the largest oil producing fields in the Middle East, is situated in offshore Arabian Gulf about 80 km North West of Abu Dhabi Emirate island.

The field was discovered in 1963, development started in 1977 by utilizing conventional drilling methods. Horizontal drilling was introduced in 1989 and an extensive multilateral drilling was implemented in the last two years.

The concept of using horizontal wells to improve recovery and controlling sweep efficiency was introduced in the oil industry since 1920s. In recent years thousands of horizontal wells have been drilled world-wide to achieve this concept at a lower monetary investment.

The extensive experience of steerable drilling system and remarkable improvement in horizontal drilling technology, encouraged ZADCO to drill complex multilateral horizontal wells.
Ensuring Materials Procurement Quality through Third Party Inspection and Materials Certification – The ADCO way
Authors: Dhamija Lalit K.
Published: December 2007

Operating companies buy materials worth million of dollars every month. There are numerous cases where materials received are not as per the requirements and this results in significant losses in terms of down time and costs of corrective actions required to procure the desired materials.

In the oil and gas industry many operating companies have reported that the lack of "fitness for purpose" due to non-conformances costs more than 10% of equipment costs. Users, engineers, purchasers & inspectors of materials need to give the proper attention which material procurement deserves. Necessary care is required in preparing buying description/ selecting specifications of the materials and on improving methods of procurement, inspection, traceability, certification and re-certification. Third Party Inspection (TPI) is a powerful tool to ensure quality of purchases made by a company. TPI, if properly applied, prevents cost and time over-runs. For TPI to be effective, a proper methodology has to be followed at various procurement stages.

This paper describes the ADCO'S activities in ensuring that procurement quality is achieved in a cost and time effective manner. The use of materials certification is also explained. There is a discussion on what to look for in a material certificate and why material certificates are rejected.

The paper also describes issues relating to management of TPI activities and various ADCO initiatives to improve procurement quality.
An Estimate of the Uncertainty of Residual Oil Saturation Derived from Log-Inject-Log Measurements from a Middle East Carbonate Reservoir
Authors: Wiltgen Nick , Al-Merikhi Sultan , Al-Othman Ibrahim
Published: December 2007

abstract

As production declines in a reservoir, management is confronted with the question: Do we have sufficient hydrocarbons remaining for an improved recovery project to be economically viable? The answer requires a knowledge of the remaining recoverable reserves which are determined from the residual oil saturation (Sor). Hence Sor is essential to calculate the reserves that can be produced by the proposed project. The additional income can then be compared with the required expenditures necessary for its implementation to enable establishing whether the project meets the required profitability criteria.

I lowever, a project must not be judged on profitability alone. Its riskiness must also be taken into account. If we have two projects with the same profitability, the one that is less risky is obviously preferred. Riskiness can be defined as a measure of the uncertainty of achieving expected results. Riskiness depends on many factors but one of the most crucial will be the uncertainty in the recoverable reserves which is directly dependent on the uncertainty in the measured Sor. Clearly an assessment of the uncertainty in Sor is very important.
Applications of Coiled Tubing in Zadco Wells
Authors: Hassan M. M. , Abu Sharkh A. F.
Published: December 2007

Recent improvements in coiled tubing technology and reliability have resulted in an impressive participation of coiled tubing units in drilling / completion operations and well services such as stimulation, liquid nitrogen lifting, testing, logging etc. for oil and gas wells.

This paper presents an operational overview of ZADCO experience in applications of coiled tubing (C/T) as follows: a) velocity strings in wedk flow well, b) pack off strings for corroded production tubings c) acid conveyer for stimulating deviated and horizontal wells.

The case history of running C/T as a velocity string in two ZADCO wells has resulted in a continuous flowing wells and a marginal improvement in the wells' productivity.

The program for utilizing C/T as pack off string in ZADCO wells was not implemented yet due to logistics problems and changes in the workover program. However, a brief theoretical plan / running procedure is highlighted.

Also, this paper presents the benefits of using C/T for placing acid across low permeable subreservoirs which results in maximizing the well's oil production.
Predicting the Initial Reserve and the Performance of High Pressure Gas Reservoirs
Authors: Elsharkawy Adel M.
Published: December 2007

A challenging problem confronting reservoir engineers these days is the estimation of the initial gas in-place and prediction of the performance of high pressure gas reservoirs because of the effect of formation compressibility and possible water influx from small associated aquifer or embedded shales. Several material balance models have been proposed to estimate the initial gas in-place and predict the prevailing production mechanisms for such reservoirs. However, most of these models have prier assumption about either the formation compressibility or the aquifer size.

This paper presents a material balance solution plot. The solution includes gas expansion, reservoir condensate expansion, rock expansion, formation water expansion, water influx from associated aquifer, water influx from embedded shales, and gas evolved from formation water.

Application of the material balance solution plot described in this paper shows that this solution plot successfully estimate the initial gas in-place and predict the prevailing reservoir production mechanism. Comparison of the new solution explained in this paper with the others shows that the new solution is more simple and accurate than the others.