bluuebunny/crossref_metadata_2025 huggingface dataset:
Rehabilitating Marine Jetty with Cathodic Protection
Authors: Siddiqui Mohammed S.
Published: June 2009

The application of cathodic protection in concrete is different from that in soil, because of varying concrete conductivity, and for the fact that any discontinuities in the reinforcement can result in stray current corrosion. The paper highlight the challenges in retrofitting impressed current cathodic protection in marine structures where concrete damage and rebar corrosion had already been detected in previous underwater inspections.

Ideally the embedded bars are a good match with concrete with respect to their thermal expansion, as well as due to the protective passive film formed in the alkaline cement. However corrosion of the reinforcing bars begins when the concrete does not fully cover the steel, and when the chloride ions present in the sea water penetrate the cement. The corrosion products occupy greater volume than the original steel, generating expansive forces and resulting in cracking, delamination and spalling of concrete cover. Installation of CP is very cost effective repair option for the concrete that is contaminated with chloride but with sufficient remaining strength.

Anode material suitable for the complicated jetty structure is a combination of internal discrete anodes and conductive meshes to achieve optimum current distribution. With the marine environment conditions, a high current density of 8-20mA/m2 is required. For effective CP, the individual areas need to be classified into zones to take care of the variation in cover and geometry of the structure. Each zone has individual power supplies, reference cells and controls on the current, voltage, potential and depolarization.

The automatic monitoring system has data storage facility, control units and softwares that can download data over a suitable time period that depends on the variations in the environment. Tests like the 24 hour depolarization (100mV criteria) can be used to assess the protection levels of the marine structure.
Improving Oil In Place Estimation through an Improve Water Saturation Prediction – A Case Study in the Middle East
Authors: Hammadi Mohamed Al , Al-Maskari Shamsa , Radwan El-Sayed
Published: June 2009

Accurate predictions of water saturation were achieved through an integrated process involving Petrophysics and core analysis. During reservoir evaluation, log derived water saturation inaccuracies were found due to inconsistency with production data. The conventional resistivity methods for calculating water saturation did not fully resolve this inconsistency and hence a different approach was required. The inaccuracies associated with Sw prediction from Archie's resistivity are due to a number of factors including mud invasion, presence of a dual pore system and resistivity tools physics.

In an effort to determine the true in situ water saturation and make more accurate predictions of oil in place a special study was performed. Such study involved: Cutting low invasion core in the reservoir.Using a tracer in the drilling mud to help differentiate formation water from invasion fluidsTaking Dean-Stark vertical plugs from the cores at the rig site and preserving them for laboratory analysis.Analyzing the fluids in the plugs to determine the degree of invasion.Use of plug analysis results to predict more accurate water saturation.Use vertical and horizontal resistivity measurements to identify the resistivity anisotropy and therefore, provide more accurate water saturation as compared to the conventional resistivity approach.Aquire RST-sigma log to help in data integration.Improved oil in place estimations.

The tracer allowed the core analysis to determine the percentage of invaded fluids in the plug sample and more accurately predict the true in situ saturation state of the reservoir. The results showed that the dual pore system and layering have played an important role in the invaded fluid distribution and quantity. The new saturation model allowed for corrections to log measurements providing a better representation of the reservoir properties. The use of vertical resistivity was found to be important to correct for layering and allowing to obtain results closer to the direct core measurements. The new model estimates were in much closer agreement with production test data and this resulted into improved oil in place estimations.

This paper, will discuss the methodology and data integration of Sw determination and how it lead into critical development decisions.
Onshore Multiple Attenuation Study on Abu Dhabi Seismic Data Successful at Removing Unwanted Noise
Authors: Jenaibi M. S. Al , Nahhas M. S. Al , Soroka W. L. , Cogan M.
Published: June 2009

Multiple attenuation was successfully performed on land seismic data in the difficult Abu Dhabi sand dune and sabkha environment. The keys to success were careful analysis plus selection and application of carefully designed data-adaptive multiple attenuation workflows. The demultiple success on the South East Abu Dhabi seismic data described in this paper was the result of a unique workflow developed specifically for this survey. Development of the workflow depended on rigorous analysis and consistent feedback from interpreters and geophysics specialists.

Multiples with similar prestack moveout with offset to the primary events were successfully modeled and removed from seismic data to produce higher quality final seismic images. Onshore seismic data from the high sand dune South-Eastern Abu Dhabi area suffers from strong ambient noise and multiples that make exploration efforts difficult. Although a variety of techniques and algorithms exist for modeling and removing multiples from seismic data, there is no single method that is appropriate for all cases. Successful projects for the most difficult onshore multiple problems are often the result of careful analysis, selection and application of the right technology and the use of an appropriate data-adaptive workflow. The demultiple success on the South East Abu Dhabi seismic data demonstrates that with the proper tools and feedback it is possible to developed a workflow that can attenuate even the most difficult multiple noise.
Compositional and PVT Analysis for Determining Liquid Dropout in Pipelines
Authors: Esmaiel T. E. H. , Qallaf A. A. A. Al
Published: June 2009

A lot of equipment is not designed to handle liquids in the operations of a gathering center or gas booster station. In the study area some compressors were having vibration problems due to amounts of liquid condensate in the flow-line caused by sudden changes in pressure and temperature.

The primary objectives of this study are to determine under what pressure and temperature conditions liquids occur and to determine the proper operating conditions. The process involves the collecting of samples in the field, lab analysis, computer EOS modeling of the fluids, and analysis of the phase regions.

Samples were collected at two different locations in the gas line. The samples were sent to the lab for compositional and PVT analysis where physical properties were measured. Compositional analysis was performed on the gas and the condensate samples and liquid dropout tests were performed on the samples.

An EOS simulator was used to characterize the samples and was tuned to match the PVT data. The tuned simulator was used to perform flash calculations calculate VLE for the samples. The simulator was used to develop phase envelopes and physical properties of the gas to determine the amount of liquid dropout at the current operating conditions. These phase envelopes were used to determine new operating conditions to avoid liquid dropout. The primary solution as anticipated was an increase in the pressure in the line to avoid the two phase region.
Sharing Patented Technology on Disposal of Oily Effluents - An Ideation, Innovation and Implementation Experience
Authors: Kapoor S , Jain A , Panwar M L
Published: June 2009

Globally, the oil majors are establishing their future environmental and social responsibility benchmarks as restructuring to their newer outlook. These concerns call for better control of emissions & releases from their operations and finally handling of decommissioning of oil / gas installations etc. The national oil company ONGC, currently produces about 0.12 million m3 per day of water from its various on land & offshore oil assets. Oil field waters contain highly toxic organic and inorganic substances, which have deleterious effect on local flora and fauna. The various conventional methods currently in vogue are less satisfactory as being less environment friendly, less cost effective and more energy demanding. The petroleum industry has made enormous strides in improving its environmental operations.

A technique coined as electroflotation has been developed for the separation of hydrocarbons from oil field waters. A regulated low direct current is passed through identified electrodes to treat the effluent resulting in separation of oil. The designed tiny bubbles of hydrogen & oxygen (~ 50 micron) through strategic electrode stacking produced during electrolysis of water accelerate its migration to surface. The oil droplets coalesce at the surface to form an oily layer, which is skimmed off. Various parameters governing the process were optimized on bench scale followed by its validation at pilot level. A total of nearly 200 m3 effluent for over 250 hours was treated through this technique in an oil field of Indian Western on land oil province. Nearly 200 chemical assays of inlet and outlet water were estimated for total oil content. The oil content of treated effluents was less than 10 PPM that met the laid standards. The system has additional advantage, due to bubbling out of oxygen during process, which improves the BOD & COD of the treated effluent.

The technique holds wider potential for its application in treating oily water produced during field operations and is also accredited with patent # 209854 & SPE update -21 Nov 2007 (Facilities (PFC), Production (PO), Central Asia). This innovative technology is ready to open new doors for its application to treat oily effluents in both upstream & downstream segments of oil sector & ready for commercialization. Acouple of global techno-economic enquries have also generated business interest.
Utilizing Real Time Logging While Drilling Resistivity Imaging to Identify Fracture Corridors in a highly fractured Carbonate Reservoir
Authors: Gezeery Taher El , Saqran Fawaz Al , Archibong Ekpo Ita , Al-Radhi Somaya
Published: June 2009

The Minagish structure in southwest corner of Kuwait is a multi reservoir field. One of the potential reservoirs is the Mishrif formation. Developed as a limestone, sedimented in a mid-ramp environment, it generally consists of fine-grained packstones to wackstones that is highly bioturbated. The average thickness is about 300 ft with an average Net of 170ft in the upper layers. An average porosity value will be around 15% and permeability ranges between 0.001-17 mD. The oil in the Mishrif is highly viscous and production is normally enhanced by fractures in the upper Mishrif layers as they act as the main permeability conduit for the main storage below.

The second Mishrif layer unit 2 (M9 & M8) is a fairly high porous peloidal packstone to grainstones sequence that is highly fractured at the upper 15 feet of the layer's "dual porosity system". The fracture corridors within the layer improve permeability, thereby making it a good potential for horizontal well placement. It was impossible to reach the observed production rates from matrix without one or two major fluid conductive fracture corridors.

The main storage Mishrif layer unit 3 (M7 & M6) is within a 15% porosity layer that is 10–15 ft thick and contains a large volume of oil.

Previous wireline image studies carried out identified these layers and their corresponding fractures, but because most of the studied wells were vertical, the fracture corridors could not be properly related to presence of faults in the field.

This paper aims at showing how effective Logging While Drilling (LWD) resistivity images based on laterolog principle were useful in real time to identify the different layers within the Mishrif reservoir and establish the relationship between the fracture corridors and the intersected faults in a long horizontal well that posed a risk to data acquisition with standard wireline pipe conveyed logging.
Health Reporting System in the Oil & Gas Business
Authors: Zappador Claudio , Gomez Guillermo , Madera Angelo , Uberti Filippo
Published: June 2009

Eni E&P Division is strongly committed to achieve excellence in managing the health of its employees in all operative activities. For this purpose a Health Management System (HMS) has been developed according to the OHSAS 18001 regulation and international health standards and best practice.

To build the Health reporting system, Eni E&P have selected an appropriate set of Health KPI (Key Performance Indicators) representing a critical step for ensuring the continuous improvement of health performance. A growing demand for improved health management come from many stakeholders (e.g. financial investors, NGO, etc) and complies the natural desire of all citizens to be informed on the prevention of health risks that may raise from operations. Currently there is no globally applied set of performance indicators in the Oil & Gas industry and updated guidelines have been issued by OGP/IPIECA only recently.

A list of "Reactive" and "Proactive" indicators has been implemented for monitoring the implementation of HMS and the overall health performance worldwide. A sustainability analysis has been introduced and allowed us to identify better the critical areas of improvement to be supported with a more defined set of KPI. A training program has been developed for spreading awareness and improving the accuracy of health reporting process.

The implementation of Health Reporting System has been established in the following steps: –Identification of representative KPI (in line with international and Eni guidelines)–Company Standard for Health Reporting & Performance Assessment;–Systematic Health Reporting from Business units;–Performance monitoring;–Sustainability analysis and identification of critical KPI;–Training program;–Feed back: Sustainability/HSE report; Annual Objectives and HSE planning.–Future: Benchmarking internal/external KPI; new KPI; improved data analysis.
An Integrated Case Study from Seismic to Simulation through Geostatistical Inversion
Authors: Soni S. , Littmann W. , Timko D. , Karkooti H. , Karimi S. , Kazemshiroodi S.
Published: June 2009

The field is located in the Persian Gulf and has been producing for the last 30 years with a strong natural aquifer support. The clastic reservoir exhibits highly heterogeneous permeability combined with shale streaks and therefore presents complex flow behavior.

This paper describes the iterative seismic to simulation workflow followed to create a fine scale reservoir static and dynamic simulation model consistent with all available engineering, geologic and geophysical data. The process involved integration of static and dynamic modelling workflows. History matching the production data indicates locations with incorrect information in the static model, which can be corrected and re-exported for the dynamic model in very short time. The integration of static and dynamic modelling is seen as essential for the further commercial development of the field.

A comprehensive integrated study was conducted starting from petrophysical log evaluation and resulting in fine scale reservoir models on a geo-cellular grid. To reduce the uncertainty, a model was created using a geostatistical inversion technique which honoured both geologic and seismic information. The use of high resolution geostatistical inversion provided good and reliable estimates of porosity and lithology away from the wells. The porosity and lithology models were further tested on history matching 92 producing wells for 30 years. The quick match resulted in less uncertainty of porosity and higher confidence in the prediction models.

The history matched model is predicted further to define different potential development scenarios. It is now 3 years since all the data used in the study was acquired and the current field production matches with the model prediction. The models created using geostatistical inversion proved to be robust and predictive for the field development.
Treatment and Recovery of Oil-Based Sludge Using Solvent Extraction
Authors: Abouelnasr Dana M. , Zubaidy Essam
Published: June 2009

Oil-based sludge is a common by-product of petroleum processing, storage, and transport. It is currently treated to a minor extent before it is disposed of in a landfill. However, as energy costs rise, and environmental impacts become of greater concern, there is increased interest in developing a means to reduce the amount and toxicity of this waste, and to recover useful materials.

Solvent extraction was used to treat oil-based sludge from oil tankers. Methyl ethyl ketone (MEK) and LPG condensate were among the solvents used. Different solvent-to-waste ratios by weight were used to determine the optimum process. The mixture was then filtered, and solvent was recovered from the filtrate through distillation. The extraction and filtration steps were at ambient temperature. The recovered fuel oil was analyzed for fuel charactistics.

The maximum recovery of fuel oil occurred with a four-to-one ratio of MEK to sludge. Thirty-nine percent of the sludge mass was recovered as fuel oil using this system. On analysis, the recovered fuel oil was similar to typical fuel oils, except for elevated levels of carbon residue and sulfur.

This solvent extraction process can be implemented as a continuous process to reduce the amounts of waste oil-based sludge, while recovering valuable fuel oil.
Thermal Maturity Model of the Arabian Plate
Authors: Pietraszek-Mattner S. R. , Grabowski G. J. , Chaker R. , Maze W. B. , Ottinger G. A. , Hardy M. J.
Published: June 2009

A regional thermal maturity model of Arabian Plate petroleum source rocks was constructed using ExxonMobil's Stellar™ basin-modeling software. The model integrates new plate-wide structural maps at 19 unconformities spanning the Phanerozoic era with estimates of missing section amounts at ten major unconformities and is calibrated to regional temperature and maturity data. Timing of generation and hydrocarbon yields are constrained by kinetic analyses of samples from multiple source rock intervals. Results of the kinetics are integrated with maps of source rock distribution to arrive at the volume and extent of oil and gas generation. Finally, hydrocarbon migration from mature source rock kitchens is evaluated using depth structure-contour maps, and the results are calibrated against known hydrocarbon occurrences and geochemical correlations.

The model results highlight several important regional observations regarding timing of hydrocarbon generation and migration, distribution of hydrocarbons and integrity of regional seals. Sensitivity analyses indicate the amount of missing section affects the timing of hydrocarbon generation for selected Arabian Plate source rocks. This may be important to understand the timing of migration relative to trap formation. Some traps appear to have been filled with oil soon after they were formed. However, geochemical correlation and characterization of oils from the region suggest lateral migration of at least 150 km from some areas of mature source rock. Additionally, regional seals such as the Hith appear to limit the extent of vertical hydrocarbon migration for most hydrocarbon systems. However breaches in many regional seals, caused either by erosion, faulting or fracturing, or solution-collapse allow oil and gas to migrate vertically to younger reservoirs.
Experimental and Numerical Comparison of Flooding Schemes to Enhance Recovery of Light / Medium Heavy Oil in an Offshore Oilfield
Authors: Yang Bin , Jiang Hanqiao , Yang Shenglai , Chen Minfeng , Fang Yang
Published: June 2009

This paper shows how to develop the light/medium heavy oil reservoirs and to optimize the production in ND offshore oilfield by using experimental and numerical technologies. The reservoirs in ND oilfield which has large reserves of the light/medium heavy oil (viscosity from 50 to 750 mPa·s) are very complex; faults are well developed and divide the oilfield into many blocks. The current drive mechanism is a water flooding or natural depletion bringing the average pressure down sharply, and reaches its production/economic limit in some of the similar offshore heavy oil reservoirs. The low primary recovery factor and the potentially vast remaining oil in these reservoirs necessitates considering applying improved oil recovery technologies for reservoirs in ND oilfield. Both physical tests and numerical simulations on different kinds of flooding schemes are examined and compared in this paper to enhance the recovery of light/medium heavy oil reservoirs. More specifically, water flooding schemes under different injected water temperatures (50°C, 150°C, 200°C), gas flooding schemes using carbon dioxide/natural gas medium, WAG schemes by carbon dioxide are conducted respectively. Other flooding schemes, such as cyclic steaming, steam flooding and combustion process are not investigated since they are normally unable to perform well in light/medium heavy oil reservoirs. We also present an example of the use of the ND-B1 reservoir as a typical model by simulating the flooding schemes. The results of numerical simulation were derived for comparing with experiments parameters. This paper provides a good reference for other similar reservoirs in China to recover light/medium viscosity heavy oil.
Carbonate Reservoir Rock Typing – The Link between Geology and SCAL
Authors: Gomes Jorge S. , Ribeiro Maria Teresa , Strohmenger Christian J. , Negahban Shahin , Kalam Mohammed Zubair
Published: June 2009

Reservoir rock typing is a process by which geological facies are characterized by their dynamic behavior. The dynamic behavior of the facies is assessed by studying the rock texture, the diagenetic processes which overprinted the initial fabric, and the interaction between the rock itself and the fluids. Porosity, permeability and pore size distributions characterize the rock texture while capillary pressure, relative permeability and wettability describe the rock-fluid interaction.

Reservoir rock typing is a synergetic process between geology and petrophysics/SCAL. It is therefore a process by which various petrophysical parameters and dynamic measurements obtained from SCAL are integrated in a consistent manner with geological facies (lithofacies) to estimate their flow (dynamic) behavior.

The relationships between lithofacies and reservoir rock types (RRTs) is complex because of the inter-play between facies, diagenetic processes and the rock-fluid interaction (wettability changes) in the reservoir. Similar lithofacies, deposited under the same depositional environments, may exhibit different petrophysical properties due to diagenesis. Therefore, lithofacies deposited under similar geological conditions may experience different diagenetic processes resulting in different petrophysical groups with distinct porosity-permeability relationship, capillary pressure profile and water saturation (Sw) for a given height above the Free Water Level (FWL). On the contrary, lithofacies deposited in different depositional environments, might exhibit similar petrophysical properties and dynamic behavior.

The authors emphasize on the need to have a good understanding of the original facies, depositional environments, subsequent diagenetic processes and rock-fluid interaction (via SCAL) to be able to unravel the relationships between lithofacies, petrophysical groups and rock types.

A workflow for carbonate rock typing addressing some of the industry pitfalls and the differences between lithofacies, petrophysical groups and rock types are presented in this paper.
The Combination of Mechanical Separation with Chemical Separation to Treat Waste Water Offshore
Authors: Grégoire Franck
Published: June 2009

Offshore rigs and all the other vessels or installations used in the oil and gas industry very often handle complex mixtures of oil, water and solids, typically in large volumes. Treatment of these waste streams and the content of the discharge to the local environment is frequently regulated by stringent legislation, including regulations stipulated by the International Maritime Organization.

These complicated, contaminated water streams-including bilge water, open deck drains, tank wash drains and drill-floor drains-vary considerably in composition and physical properties. Even if they often contain different types of solids or oils, the main challenge for separation systems is to break down complex emulsions.

It is widely accepted that conventional waste water stream separation methods are ineffective and costly processes. At the same time, legislation and public concerns are increasing the pressure put on differing oil and gas companies to respect the environment. To reach high performances at a low life cycle cost, the modern solution for treating these streams combines mechanical separation and chemical separation. With the use of site operational data, this paper will compare the traditional system and the new process solution developed and tested in cooperation with Maersk Drilling. Other benefits of such systems will also be reviewed, such as their compact, low weight nature and their swift reaction time to the typical variations encountered with these types of effluent water drains.
Data-Driven Seismic Repeatability Evaluation on a Carbonate Reservoir Offshore Abu Dhabi
Authors: Akama Kenichi , Takahashi Isao , Hagiwara Hiroshi , Sultan Akmal A.
Published: June 2009

Field repeatability of OBC 3D seismic data is investigated for evaluating feasibility of time-lapse (4D) seismic survey for monitoring water saturation in a carbonate reservoir in the Middle East. We use co-located data sets, which were acquired in a small part of a giant 3D survey by re-deployed shots/receivers at a short time interval, between which no reservoir change is supposed.

Both pre- and post-stack seismic data are examined using two repeatability indices: normalized root mean square (NRMS) and predictability, each complementarily quantifying the similarity of two seismic traces, i.e., data repeatability. For pre-stack data, source-receiver mis-location along the offset orientation is found to control the repeatability. Post-stack repeatability NRMS evaluated after basic data processing including noise removal, stacking, and time shift, turns out to be around 10 %. The presence of noise and static shift severely degrades repeatability in post-stack. This data-driven repeatability evaluation takes account of the influences from shot/receiver mis-positioning, source-generated coherent and incoherent noise, and location-dependent near surface effect, which conventional approaches may under-estimate.

The post-stack repeatability, however, is evaluated in a small area and can be laterally variable, since the 3D seismic data quality is strongly area-dependent. We therefore correlate the NRMS with "snapshot" 3D S/N (SN ratio of a 3D) of a single set of the repeated 3D and then use this relation for extrapolating the NRMS to the entire field through 3D S/N of the full field 3D. Combining this analysis with the result of our rock physics modeling, which reveals the magnitude of expected change in reservoir response, we conclude the feasibility of 4D seismic technique in this field is area-dependent.

The proposed procedure provides more realistic area-dependent 4D repeatability than conventional approaches.
The DuPont Experience in Sustainability: Lessons Learned
Authors: Alam Badar
Published: June 2009

The corporate response to environmental issues has changed over the years and is changing now to meet the demands of sustainability. There are four opportunities for change in achieving sustainability: balancing the size and scope of environmental issues; resolving conflicts between individual or corporate interests and the common good; realigning the current corporate tendency to focus on improving existing systems and processes rather on transformational changes; and reframing the preference for solving problems rather than on seeking and benefiting from new opportunities.

The chief priorities are to: Reduce the corporate environmental footprintObtain outside inputBecome a company geared to meet the challenges of this new century.

But the real challenge lies in identifying and evaluating new business opportunities in a carbon-constrained world. Added to the environmental challenge is the need to navigate the scientific, political, and economic uncertainties that affect business decisions and timing.

Yet meeting the environmental challenge is possible. It begins with analyzing what you do and understanding what your customers need, then meeting those needs. One key to doing this is organizational integration; another is stakeholder engagement.

The following are required to achieve sustainable growth: A visionA championMeasurable goalsStrategic reviewsRecognition of accomplishmentRelationships with relevant outside groups and individuals

In light of efforts over the past 30 years, in light of the results obtained, and in light of the lessons learned from those results, sustainable growth can be achieved.
Simulating the Outcrop: Surface To Subsurface Integration of a Carbonate Reservoir, Khuff Formation, Oman
Authors: Reijnders Gert-Jan , Al-Mohannadi Nasser , Pöppelreiter Michael , Finlay Sharon , Bodewitz Gerard , Al-Oreibi Lama , Zampetti Valentina , Al-Kindy Sulaiman , Amthor Joachim , Kohrer Bastian , Aigner Thomas
Published: June 2009

Careful gathering and analysis of outcrop analogue data is a valuable data source for enhancing the understanding of analogue hydrocarbon reservoirs. However, information from outcrops is commonly limited to static descriptions, i.e. reservoir body dimension and geometry.

Figure 1 Permo-Triassic Section exposed at Jebel Al Akhdar. Visible is a large-scale layer cake-type carbonate ramp made up of thin but laterally extensive units. The formation has been subdivided into six composite sequences (KS1 shown in red to KS6 shown in dark blue). The main facies types are: 1 graded peloidal oolitic packstones to grainstones, 2 mottled and rooted mudstones, 3 graded oolitic grainstones, 4 cross-bedded oolitic grainstones.
Multiphase Pump Implementation at Tembungo-B Platform for Petronas Carigali Sabah Operation SBO, Malaysia Sharing Best Practices
Authors: Nor A'shikin Sharifah , Rakam Royan
Published: June 2009

Tembungo-B (TBG-B), an unmanned platform of Tembungo field, is located in the northern part of East Malaysia, about 80km north west of Kota Kinabalu This platform was designed as unmanned platform which uses natural flow to transport the oil from all wells to the main platform, Tembungo-A. It contributes to more than 80% of overall Tembungo field production where, the reserves mainly consist of low pressure (LP) wells. However, the decrease in production was observed over time due to the backpressure imposed on the LP wells. The LP wells flow intermittently and when the trunkline pressure exceeds the flow tubing head pressures (FTHP), these wells quit. Multiphase pumping technology, being the first implementation in Malaysia at offshore installation, has been installed at TBG-B as a mitigation measure to help these wells producing.

Multiphase pumping technology is capable of handling multiphase crude oil, which in the form of liquid and gas, without going through separation. The technology has benefited the production processes as TBG-B is transporting the crude using natural flow from wells directly to the receiving trunkline. This eliminates the need of having separation equipments to cater for the separation processes of gas and liquid which further reduce the capital and operating expenses cost in oil production. This paper discusses the overview of multiphase pumping technology and the gain in oil production after the implementation of the technology at the field.
A New Workflow for Comprehensive Petrophysical Characterization of Carbonate Reservoirs Drilled with Water-Base Muds
Authors: Gyllensten Asbjorn , Al-Hammadi Mohamed Ibrahim , Abousrafa Emhemed , Boyd Austin , Ramamoorthy Raghu , Neumann Steve , Neville Thomas J.
Published: June 2009

One of the top concerns for carbonate reservoir evaluation is the effect of rock texture on permeability, capillary pressure and relative permeability. Recent advances in log analysis combined with new logging sensors that are sensitive to carbonate rock texture have led to an improved workflow for petrophysical analysis of carbonates. The authors have earlier described an approach to estimating permeability in carbonates from borehole NMR logs and electrical images, and have earlier studied the relationship between NMR T2 distributions and capillary pressure curves in carbonates. Additional enhancements have been made to this workflow to include estimates of relative permeability by modeling invasion of mud filtrate utilizing a fluid flow model in combination with array resistivity logs. Analyzing relative permeability in conjunction with formation permeability and capillary pressure leads to new insights in log-based rock typing for comparison with Special Core Analysis (SCAL) data. This workflow is presented in the form of a case study of a carbonate well in the UAE. The workflow will be reviewed in its entirety with particular emphasis on the relationship between log rock texture and permeability, capillary pressure and relative permeability.
Control of Sulfate Reducing Bacteria in Oil & Gas Pipelines
Authors: Lohithesh M. D. , Agnihotri A. K. , Lal Banwari
Published: June 2009

One of the major economical loss faced by the oil and gas corporate are due to the corrosion in the pipelines. The internal corrosion of the pipelines is basically caused by sulfate reducing bacteria (SRB). The overall goal of the pipeline industry must be to preserve the pipeline as an asset as there is a huge cost associated with its replacement.

Thus there is a requirement for developing a strategy for controlling the SRB population of oil and gas pipelines. The growth of SRB and their secondary metabolites in pipelines causes surface modifications, which can induce a more complex corrosion process. The outcome of the research will be advantageous to the oil and gas industry of the country. Thirty-four formation water samples were screened from 3 ONGC sites including Bombay high offshore, Gandhar and Ahmedabad. The presence of various species of SRB strains were identified as Anaerobaculum mobile, Thermodesulfovibrio yellowstonii, Desulfovibrio vulgaris, Thermotoga neapaitana, Clostridium sporogenes, Clostridium bifermentas, Desulfomatoculum kuznetsorii, Thermotoga hypogea by 16S rDNA gene sequencing. In this approach, biocides were screened, using different chemical laboratory techniques, to determine their effect upon a SRB population. Out of 15 chemical biocides, amine was effective against SRB at 50-ppm and above concentration. This will facilitate us with an efficient, and effective biocide to save the oil pipelines from the catastrophic effects of SRB.
Developing Marginal Fields In The Niger Delta: Recovery & Economics Can Be Better Than Currently Estimated
Authors: Uwaga Anthony O.
Published: June 2009

The main objective of the Marginal Fields Programme (MFP) initiated by the Federal Government is to enhance indigenous participation in the exploration and production of hydrocarbon in the Niger Delta. Under the MFP initiative, backed by the Petroleum (Amendment) Decree Act No. 23 of 1996, holders of Oil Mining License (OML) were required to farm-out fields that have remained unproduced for at least 10 years to indigenous Nigerian Exploration & Production (E&P) companies1.

Majority, if not all, of these farmed-out fields are classified as marginal fields. A marginal field is defined as "a field that may not produce enough net income to make it worth developing at a given time; should technical or economic conditions change, such a field may become commercial"2. Thus the task facing the E&P companies that were given the farmed-out fields is how to make their development attractive economically i.e. produce enough net income.

Changing the technical and/or economic conditions of these marginal fields is made challenging by virtue of the very limited technical data available. It is common knowledge that much attention has not been given to these fields in the past and is the main reason why they have remained unproduced.

Leveraging on the large footprint of the Shell Petroleum Development Company (SPDC) across the Niger Delta and making use of her PVT database for sampled, analysed and/or producing fields, the Niger Delta region was sub-divided into geological units based on similarity in observed PVT parameters.

With the work done and presented in this paper, knowing the geological location of any marginal field in the Niger Delta is enough to fairly estimate its basic PVT properties.

The paper goes further to show, using a case study through a dynamic simulation model built for a marginal field, that previous PVT estimations, recoveries and development economics for the case study marginal field were pessimistic.

Extending the results of the case study it is the position of this paper that some other marginal fields in the Niger Delta will benefit from a PVT, recovery and development economics review. Their development can produce enough net income.
Integrating Microseismic Monitoring With Well Completions, Reservoir Behavior, and Rock Mechanics
Authors: Warpinski N. R.
Published: June 2009

Microseismic monitoring has proved to be a valuable technology for assessing and optimizing hydraulic fracturing in a host of tight sand and gas shale reservoirs. Parameters such as fracture length, height, azimuth, and asymmetry are readily identified, but this technology can also be useful for understanding staging effectiveness, stimulated volume, complexity and network growth, natural fractures, stress azimuth and changes in that azimuth, fault interactions, and reservoir behavior as a result of the treatment. Various published data sets are examined to show how both quantitative and qualitative information about the fracturing behavior, completion effectiveness, and reservoir behavior can be usefully extracted from the microseismic data. Examples will include both vertical and horizontal wells, relatively planar and network fracture systems, various staging and diversion techniques, and faulted and naturally fractured reservoir response.
The Effect of Micro-Emulsions On High and Low GOR Gas Wells
Authors: Crafton J. W. , Penny G. , Burkett B.
Published: June 2009

An extensive, on-going investigation into the effectiveness of a micro-emulsion (ME) as a stimulation fluid additive is being conducted. Results from a population of 114 wells and 498 stimulation stages of hydraulic fracture stimulation provide the basis for this report. As part of the basis for the performance analysis, twenty four of the wells are producing from the Lance interval in the northeastern Pinedale Anticline area of the Green River Basin, Wyoming. The remaining 90 wells produce from the northern Denver-Julesburg Basin Codell and Niobrara formations. In both data sets about half of the wells had 1.5 gallons of ME per thousand used throughout the fracture stimulations, but at no other time during in-well operations. The stimulation fluid systems in the remaining wells contained no similar interfacial tension / surfactant system. Based on the performance matched reservoir properties and degree of effective stimulation, these comparisons and other performance metrics were used to assess the potential benefit arising from using ME. The determination of potential benefit was assessed using classical statistical methods to ensure that the interpretation was as unbiased as possible. From that analysis, there is distinct and clear benefit to be gained from using the micro-emulsion to facilitate placing the fracture stimulations, to increase effective fracture length and especially to increase hydrocarbon recovery from the wells in which the micro-emulsion system is used.
Integrating Solid Expandables, Swellables, and Hydra Jet Perforating for Optimized Multizone Fractured Wellbores
Authors: Durst D. G.
Published: June 2009

Growing energy demand is leading the industry to re-evaluate resources found in challenging conditions such as unconventional formations. Cost-effective development of these resources depends upon strategic application of advancing production solution technologies. To enhance production and improve recovery processes, more efficient perforating and fracturing methods have evolved along with advancements in wellbore production hardware via use of solid expandable tubulars or combinations of solid expandable and conventional tubulars.

Expandable technology applied as a completion/production string provides an optimized or customized wellbore that can facilitate increased fracturing rates, resulting in improved conductivity and enhanced hydrocarbon production. A fully expandable or combination system with standard casing can provide an integral component in either new wells or re-entry wells where low-permeability reservoirs, such as those characteristic of unconventional formations, require isolation and separation for pinpoint hydraulic fracturing.

Although successful stimulation is routinely attained from hydraulic fracturing, ancillary downhole tools, such as conventional completion equipment, often compromise results by restricting flow and affecting pressure performance. Solid expandable swellable systems can optimize the fracturing parameters by maintaining larger diameters and providing positive seals for selective multi-zone isolation purposes. These production systems consist of expanded sealing sections in combination with expandable or conventional intermediate tubulars utilizing premium connections thereby providing a superior completion solution for mechanical diversion.

Right-sizing the wellbore to the reservoir can provide operators significant cost savings, even more so during these economic times. Utilizing larger diameter expandables in the horizontal wellbore allows operators to first optimize the fracture program to the potential of the reservoir then develop the well program to accommodate the fracturing rates and volumes as well as the surface pumping facilities. This can result in slimmer surface and intermediate sections at much lower cost without compromising the overall stimulation completion program nor planned production and recovery.

This paper will discuss the integration of expandable systems with other technologies and cite case histories to illustrate the effectiveness of solid expandable systems in enhanced production and fracturing applications.
Coiled Tubing Deployed Resin Treatment Remediates Proppant and Formation Sand Flowback in High-Temperature Wells: A Field Study in South Texas
Authors: Durkee M. , Peak Z. T. , Montes M. B. , Nguyen P. D.
Published: June 2009

Flowback of proppant and formation sand can often become problematic for operators because the solids cause equipment damage, costly cleanup treatments, and potential loss of production. These flowback problems are often compounded in severity in wells with high temperature and high pressure. Operators seek reliable solutions to (1) eliminate the need for frequent remedial cleanouts and surface equipment replacement and (2) to maximize revenues by increasing and maintaining production rates.

This paper presents a field case study that discusses the remedial treatments and knowledge gained from more than 30 wells in south Texas where proppant and formation-sand flowback problems have been encountered by the operator. It also discusses the development and treatment processes using low-viscosity consolidating agents to be applied in the treatments. Examples presented illustrate how the problems were successfully overcome in these high-temperature wells.

Field results indicate that more than 90% of these consolidation treatments have effectively stopped the flowback of proppant and formation sand while allowing the production rates of the wells to be increased. These treatments have drastically decreased the number of workovers compared to the period before their treatments, or compared to the offset wells in the same field where consolidation treatments were not performed. This study demonstrated that an effective coating of a curable resin on the proppant and formation sand close to the wellbore is necessary to help maximize the consolidation bonding between grains within the pack while minimizing any reduction of its permeability.

This new remedial-treatment process greatly enhances the effectiveness of fluid placement into the propped fractures, regardless of the number of perforation intervals and their lengths and without mechanical isolation between the intervals. The simplicity of treatment helps make remediation economically feasible, especially in wells with marginal reserves.
An Advanced Injection System For Chemical Activation Of Blast Furnace Slag Cement
Authors: Brooks Fred A. , Lang William J. , Daves Thomas W.
Published: June 2009

Granulated, hydraulic Blast Furnace Slag (BFS) is finding application as a well-cementing material mixed either in water or in water-based drilling fluids. Unlike Portland cement-based systems, which have been used for well cementing for almost a century, the BFS formulations require chemical activators to achieve set for most well conditions. The most widely used activators are soluble inorganic alkalies.

This paper reports the design, development, and testing of the Proportioning Injector Unit (PIU).This device is placed in the flow line (between the drilling rig mud pumps and the cementing head) when using BFS to cement casing in a well. The PIU includes an inline flow meter to continuously monitor the flow rate of a BFS cement lacking one or more of the activators. The data from the flow meter allows a programmable controller to operate the positive displacement pumps ensuring a precise, predetermined amount of activator solution is injected into the stream prior to the now activated BFS cement entering the cementing head.

A prototype PIU has been fabricated, yard tested, and used for a test mix in the field. It is now available for use in conjunction with drilling rig mud handling equipment to cement casing in wells.