bluuebunny/crossref_metadata_2025 huggingface dataset:
Novel Controlled-Release Breakers for High-Temperature Fracturing
Authors: Patil Prajakta , Muthusamy Ramesh , Pandya Nisha
Published: April 2013

Various types of breaker systems are used for viscosity degradation of fluids in fracture stimulation operations. Achieving improved fracture conductivity is one of the key advantages of using effective breaker systems, but there could be an increased risk of poor proppant placement and premature screenouts resulting from early viscosity reductions as the fluid is exposed to temperature. To resolve this issue, a controlled release of the breaker over a period of time is very desirable.

This paper highlights the controlled release of encapsulated oxidizers and chelating types of breakers that are effective in bottomhole static temperatures (BHSTs) up to 275°F. Oxidizers without encapsulation begin to decompose fluids at low to moderate temperature, which can lead to a rapid decrease in gel viscosity before completion of the fracturing operation. Neat chelating breakers can absorb the crosslinker rapidly; thus, little to no crosslinking action would be present, even at moderate temperatures. A newly developed encapsulant makes oxidizers and chelating agents viable for reducing the crosslinked viscosity gradually with temperature.

The new encapsulant is a blend of selected polymers that release the active breaker through diffusion. It is possible to optimize the release rate of a breaker by simply adjusting its ratio in a polymer blend. The controlled release of a breaker through an encapsulant was evaluated at 200°F under static conditions. The dynamic rheology of fracturing fluids was also studied as a function of encapsulated breaker concentration in temperatures up to 275°F. The results derived from this investigation are of significant importance to the oilfield industry.
Field Example of the Application of a Probabilistic Workflow to Forecast Future Development Potential in a Heterogeneous Fluviatile Reservoir
Authors: Dros A. N. , Benhammadi Z.. , Vernain-Perriot V..
Published: April 2013

Probabilistic workflows become more and more applied in the current industry. Especially in fields with large uncertainties or property variations these techniques allow to capture the possible realizations of the reservoir and the range of outcomes for applied field development scenarios.

This document describes the application of a probabilistic workflow on a field located in Northern Africa. The field is an oil field producing from a fluvial formation. It has produced 0.5 MM stb to date from one production well.

In order to assess the future potential of the field, multiple static realizations were created based on probabilistic modelling of uncertainties in structure, channel characteristics (geometry, amount over the field and orientation) and properties. These static models were consequently initialized in a dynamic modelling environment. Several thousand static models were screened revealing the information implicitly stored in the data resulting in seven realizations for which an acceptable history match was achieved. All matching realizations showed a channel belt oriented in a SW-NE direction, apparently parallel to the main fault. Within the channel belt the net sand is high, but the area away from it is either predominantly non-reservoir or very poorly connected to the main channel belt. Some uncertainties remain, the most significant being the structure and the amount and distribution of the net reservoir and as a result the STOIIP.
Carbonate Reservoir Characterization at Different Scales: Proving the Value of Integration
Authors: Cañas Jesus A. , Junk Elmar , Essenfeld David , Ortiz Rubiel
Published: April 2013

Much has been written about carbonate reservoir complexities, heterogeneity, and data integration at different scales. However, there are not many published examples that show a comparison of producibility modeling predictions and actual field results that include data from core, advanced openhole well logs, formation testers, and drillstem tests.

In this study, we present the integration of data and measurements from advanced technologies to evaluate reservoir heterogeneity of carbonate formations on multiple scales. Quantitative textural analyses based on a comprehensive suite of petrophysical logging measurements were integrated with core data and formation testing data to characterize hydrocarbon/water transition zones and formation permeability and producibility. The offshore carbonate reservoir studied is composed of limestones and dolomites. Despite the inherent chemical complexities and hidden modes of origin, dolomites often exhibit favorable reservoir quality with high porosity and permeability properties. For this reason, E&P companies continue to predict where drilling targets are most likely to encounter these sweet spots.

Traditional permeability correlations are not effective in these systems, leading to overdependence on porosity-based reservoir descriptions to predict fluid flow. Using nonparametric regression, we have established a relationship between permeability and porosity from logs that are available fieldwide. Subsequent integration of this data with interval pressure transient test data in zones selected based on the observed rock heterogeneity enables further optimization of the final permeability correlation. The descriptions of the field examples confirm the success of this integrated approach and include the planning, real-time monitoring, and final validation of permeability and anisotropy at different scale during the exploration phase of a field.

Selecting the well locations for development using the proposed approach has proved valuable for improving field development practices. The results have led to enhanced reservoir characterization based on flow (permeability) and storage-capacity analyses (porosity partitioning), and a better understanding of the reservoir heterogeneity at different scales; the results have been used to improve drillstem test designs and reservoir production strategies.
Challenges and Practical Aspects in Commingling Different Reservoirs: Theory and Case Study
Authors: Darhim Noureldien
Published: April 2013

GS327 is a small field located 7 km east of southern Morgan field. It was discovered in May 1983 by well GS327-A1. An excellent sand quality was found in both Upper Rudeis ASL & KAREEM reservoirs (Lower Miocene). The field initial rate was about 6,000 BOPD, and after drilling 12 wells, the production hit 11,000 BOPD. After that production declined dramatically reaching 3,000 BOPD in 2011.

Currently and after an extraordinary job, GUPCO succeeded to double the field rate by commingling the totally different isolated reservoirs (ASL & KAREEM) in the well EM327-1ST1 after intensive multidisciplinary study. This paper presents the methodology of that study and analysis done to commingle two different reservoirs safely highlighting challenges and uncertainties we had in both data and procedures. It shows how to estimate the new STOOIP and how to predict the new well/reservoir performance by using a combination of MBE, Well Modeling and DCA.

The study covers three main sections of challenges; first one is Productivity of each reservoir in terms of Pressure and Fluid Mobility through different reservoirs to mitigate/evaluate cross-flow possibility, second section is Scaling Tendency issue since both reservoirs are expected to produce significant volume of water which may have different incompatible ions, third section is surface facility capacity to handle large amount of fluids expected to be produced from that multi-layer well.

In this paper, you will find an integrated work processes at which different tools were combined; MDT's and Pressure Data interpretation, Geological and Petrophysical evaluation, Water compatibility analysis in Chemical Lab, use of different Models (Well, Reservoir & IPM basis), and finally verification of the result against actual data. Through this paper, you will know how to use every piece of data to answer uncertainty or overcome a challenge resulted in a doubled production.
North Bahariya Concession Transaction-A Novel Strategy for Acquiring the Micro-Scale Producing Fields
Authors: Abdel-Nabi M.. , El-Behiry A.. , Rizk Mahmoud , Abdel-Moneim E..
Published: April 2013

Since the last decade of the twentieth century, the Egyptian government started enacting new policies aiming at attracting national and international investments through facilitating the regulations and procedures which hinder production and investment resolutions. In this concern, the laws were issued as a step to attract the investment of the Egyptian private sector, international investment and financing corporations. Of the transactions that have recently occurred is the Sale and Purchase of the 50% operatorship interest of North Bahariya Concession.

The North Bahariya Concession is an onshore oil concession located in the Western Desert of Egypt, 190 Km SW Cairo City. Currently, the concession covers two development leases namely North Bahariya and Rawda with total approximate area of 117 km2 containing six producing oil fields; Abrar, Ferdaus, Ganna, Rawda, Rayan, and the most recent field Sidra. The primary productive horizons are the Cretaceous Abu Roash 'G' and Upper Bahariya with secondary production from the Abu Roash 'E'.

This paper aims to have an outlook on the evaluation process procedures as well as address the different views on the blocks by many evaluators. The seller had a certain view for the concession potentiality while the buyer has believed in additional potentials based on which the acquisition has been evaluated.

Exploration, appraisal, and development activities have been done by the acquirer to prove/disprove the idea of the unseen, by the ex-operator, potentiality. The activities results have had a great effect on the picture of the reserves and resources estimates with new aggressive development plan.

The current estimates of OOIP, reserves, upside potential, and field development plans have been completely refurbished according to the new potentiality view as the production and reserve have been increase by 4 times. Trusting the judgment is the key to prove the ideas.
«Hot Shales» Facies Heterogeneity: Highlights from the Mineralogical and Geochemical Analyses of the Lower Silurian Source Rock of a Palaezoic Basin (SW Algeria)
Authors: Rigollet Christophe , Hofmann Andreas , Burns Suzi , Portier Eric , Paul Andreas , Kollschijn Michiel
Published: April 2013

In Northern Africa, the Lower Silurian organic-rich shales charge both intra-paleozoic and basal Triassic reservoirs and might have an important potential for shale gas. The shales were deposited in a confined marine environment during the Lower Silurian transgression. On the Gondwana scale, they are laterally discontinuous while their distribution and thickness are controlled by palaeo-reliefs inherited from tectonic and Ordovician glacial events (Luning et al., 2000). On the field-scale, the mineralogical and geochemical analyses of cutting samples indicate significant vertical and lateral facies variations, which contradict the apparent homogeneity of this formation.

The study is based on 80 cutting samples from 5 wells of a Palaezoic basin in SW Algeria, with a maximum spacing of 13 km (Fig. 1). Each sample has been analysed in terms of its mineralogy / petrography (QEMSCAN analysis) and organic matter features (Rockeval pyrolysis). The fully automated QEMSCAN system (Quantitative Evaluation of Materials by Scanning Electron Microscopy) provided a bulk modal analysis, particle maps, a textural analysis, mineral-by-mineral chemical assay and trace mineral hunt.

The cutting analysis facilitated the identification of 21 minerals, which were subsequently clustered into 5 assemblages (1) carbonate, (2) mica, Fe-oxide and siderite, (3) Clay, (4) Clay, pyrite, chlorite and feldspar and (5) remaining minor minerals. The focus of this presentation is to describe the observed heterogeneity and to discuss the parameters that control the vertical and lateral distribution of these facies (sedimentology, diagenesis...).

The Lower Silurian "Hot Shales" are highly heterogeneous and exhibit strong vertical and lateral facies variations, which might explain the complex distribution of TOC values and brittleness properties. Through a combination of geochemical and mineralogical analyses from cutting samples, it will be possible to model the source rock heterogeneity, predict the distribution of TOC values and brittleness properties and ultimately evaluate the shale gas potential.
Maximizing Cost Efficiencies through Real-Time Well Testing
Authors: Awara Abdalla , Mansilla Cidar , Fink Kevin
Published: April 2013

When well testing is conducted, the reservoir response during the initial surge to stable drawdown and pressure buildup will define productivity expectations for a new well. The quality of the reservoir fluid samples further defines the value of the reservoir assets.

To ensure that operations will be conducted safely, rig-time efficiency will be maximized, and the overall well test objectives will be met, several critical well testing decisions must be made.

This paper describes the value of real-time access to reservoir information and tools to control well testing operations. Also described is a system that has been used to provide immediate access to the reservoir through the use of wireless downhole telemetry, data acquisition and control, and instantaneous visibility of data from any location around the world. While the idea of providing access to some reservoir information in near real time is not a new concept, the system described is not dependent on formation geology and is the only one with the capability to provide access to all reservoir information in real time, perform analysis using this information, and control well testing operations remotely with the click of a mouse button. Case histories will be presented to demonstrate the capabilities of the system described.
Effect of Petrophysical Re-interpretation on Matured Fields' Development Planning and Producing Reserves Boosting Up in Abu El Gharadig Basin, Western Desert, Egypt.
Authors: Rizk Mahmoud , Rafik M.. , Ell-Behiry A , Abdel-Nabi M..
Published: April 2013

West Qarun (WQ) and Abrar fields are located in Abu El Gharadig (A/G) basin in the Egyptian Western Desert with a combined area of about (82) Km2. Drilling activities in this area were commenced in late 1980s till first oil discovery was announced by (AMOCO) in (1994), Since that; and through February 2009; a total of (4.2) MMSTB oil was produced from six wells in both fields.

This paper demonstrates that an intensive review of petrophysical parameters had led to re-discovering the actual unforeseen bigger volume of the old matured fields that had been producing since decades; resulting in boosting up the combined production levels from about 600 BOPD to about 7000 BOPD while still development activities continues to prove extensions to both field and add more reserves.

Subject fields are producing upper cretaceous reservoirs of both Abu Roash G (A/R_G) and Upper Bahariya (U.B.) formations; this area was formerly famous for low well productivity and non-encouraging economics; but after Sahara Oil and Gas Co. (SOG) received the operatorship of these oil leases in Feb 2009, a petrophysical interpretation review was applied to find out the reason behind more than 10 years of stable production rates, the review included investigating the validity of the formerly used models for interpreting the existing shaly sand that indicated high water saturations that never matched the production data; also, an individual well interpretation parameters were considered instead of the formerly generalized set of parameters over-all the fields.

The conclusion of this paper could be summarized in attracting attention to the importance of a new eye vision when considering a new evaluation of reserves of an oil field that had been formerly considered as a matured one; while still investigating each piece of information that might have over-estimated or under-estimated the never-seen reservoir volume.
First Implementation of Distributed Temperature Survey in East Africa and East Mediterranean Region Utilizing New Coiled Tubing Technology
Authors: Shaheen Tarek , El Sherif Tamer , Hassan Wael , Kamal Salah , Nabil Emad
Published: April 2013

Issran field is located 200 km east of Cairo-Egypt, producing from fractured dolomite reservoir 8-12 API oil gravity. The reservoir depth ranges from 1000-2000 ft, with BHP 300-500 psi and BHT of 120-200 F. The heavy oil viscosity is 4000 cp at standard conditions and the reservoir rock is oil wet with high H2S content. The high viscosity and low mobility of the Issran field heavy oil in contrast with the strong mobility and low viscosity of the formation water had extended the problem to a severe decline in hydro carbon production.

In an attempt to enhance the production, Steam injection had been deployed in the field to reduce the oil viscosity and hence enhance the mobility of the extra heavy oil. Enhancement in production has dramatically increased after implementing a new technique combining the Steam Injection with the Matrix Stimulation Engineering Utilizing the Fiber Optics Telemetry Enabled Coiled Tubing.

As the first time in the East Africa and East Mediterranean countries, the new technology deployed (Fiber Optics Telemetry Enabled Coiled Tubing) has provided a new dimension to the heavy oil thermal recovery by supplying a full Distributed Temperature Survey (DTS). Real time interpretation of the DTS data enabled the real time decision making during the Matrix stimulation treatment based on the actual downhole parameters. It also provided valuable data regarding mapping of the downhole steam injection utilizing coiled Tubing.

This paper assesses the effect of using the new technology in Coiled Tubing services utilizing the DTS Measurements during Matrix Stimulation Treatment in different wells. It analyses the Successful production enhancement that provided a new dimension to the extra heavy oil enhanced recovery efficiency. It also quantifies the economical added value resulting from the usage of DTS data in respect to conventional matrix stimulation with conventional Coiled Tubing.
Oil Families in the Western Getic Depression, Romania
Authors: Gheorghe S.. , Burneiu L.. , Diaconescu D.. , Sindilar V. D.
Published: April 2013

Unlike the petroleum which has been awaking the attention of the Romanian scientists since the end of the XIX-th century (Pilide, C.L.-1877, Cobalcescu, G.-1887) and the beginning of the XX-th century (Poni, P.-1900-1901 Edeleanu, L.-1907), geochemistry have been developing since `80 years and especially after 1990, when theoretical considerations joined modern technologies for oil and rock analyses.

Today we are at the same level like similar laboratories in the world because of the results obtained with the new generation tools.

There are relatively little geochemical information published in the last years on the characteristics of oils and their potential source rocks from Romania. This paper presents the first detailed data for oils from the western part of Romanian Getic Depression. It used gas-chromatography-mass spectrometry to obtain various biomarker ratios and isotopic analysis.

The Getic Depression constitutes the Tertiary foredeep developed in front of the Southern Carpathians and it lies from Dambovita Valley (in the east) to the Danube River (in the west), whereas in the south, down to the Pericarpathian Fault which delimits it from the Moesian Platform. For this work we selected the western part of Getic Depression between Jiu River (West) and Cerna River (East). 57 oils were analyzed after the fractionation into saturated hydrocarbons, aromatic hydrocarbons and nitrogen, sulfur and oxygen (NSO) compound fractions, in order to get the distribution of the biomarkers.

The results of these investigations were been evaluated and interpreted using the new PC Soft: IGI. We characterized the various oil families in more detail, observing a special and interesting case of one of the analyzed fields (Ticleni) and we say now, that we better understand the petroleum system in the studied area.
Modified Black Oil PVT Properties Correlations for Volatile Oil and Gas Condensate Reservoirs
Authors: Nassar Ibrahim S. , El-Banbi Ahmed H. , Sayyouh Mohamed H.
Published: April 2013

This work presents new Modified Black Oil (MBO) PVT properties (Rs, Rv, Bo, and Bg) correlations for volatile oil and gas condensate reservoir fluids. These new correlations do not require the use of fluid samples or EOS calculations. The correlations have the advantage of taking into consideration the effect of surface separator configuration (two and three stages) and conditions (separators pressures and temperatures).

The correlations were developed using fourteen actual reservoir fluid samples (7 gas condensates, 3 near critical fluids, and 4 volatile oils) spanning a wide range of fluid behavior and characteristics. Whitson and Torp method was used to generate Modified Black Oil (MBO) PVT properties that were used as a data set for correlations development.

The MBO PVT properties data points were generated by extracting the PVT properties of each sample using commercial PVT software program at twelve different separator conditions spanning a wide range of surface separator configuration and conditions to generate twelve curves for each sample. A statistical approach using a statistical software program (SPSS) was used to develop the new correlations models.

The results of the new models show reasonable agreement between Modified Black Oil PVT properties generated from the new correlations and the MBO properties extracted using Whitson and Torp method. The average absolute error in the correlations was 8.5% for volatile oils and 17.5% for gas condensates.

These correlations were also validated by comparing the results of modified black oil simulation using MBO PVT properties generated from these correlations to the results of full equation of state (EOS) compositional simulation. Also, the generalized material balance equation (GMBE) was used to calculate the initial oil/gas in place (IOIP/GIIP) for many simulated cases using PVT data generated from the new correlations and data generated from EOS models. The advantage of the new correlations comes from being the first in the industry (to the best of our knowledge) that explicitly take into consideration the effects of surface separators configurations (two or three stages) and conditions. Also, all input parameters in the correlations are readily available from field production data. These correlations do not require elaborate calculation procedures or PVT reports.
Part 1 - Heavy Oil Development: Statistical Analysis and Optimization of Well Patterns
Authors: Aladasani Ahmad , Salehi Saeed , Nygaard Runar , Bai Baojun
Published: April 2013

During the past two decades, the booking of unconventional hydrocarbon reserves has hiked, thereby rising significantly above published conventional hydrocarbon reserves. Unconventional hydrocarbon resources became economically viable in the 1990s after horizontal well designs achieved commercial application in the late 1980s (King, 1993). This milestone was preceded by the development of steam-assisted gravity drainage (SAGD). The objective of this paper is to conduct an in-depth review of thermal Enhanced Oil Recovery (EOR) projects, in addition to presenting a prediction model for steam EOR and a review of heavy oil well injection/production patterns. An initial screening criterion is presented for steam EOR reservoir candidate selection, which is based on 15 categories of dataset distribution taken from 274 projects. Correlations also are provided for steam EOR project variables that significantly influence oil recovery, namely, the number of injection wells. A deterministic steam EOR prediction model has been generated to guide area development versus well patterns and targeted oil production rates. Reducing the number of horizontal (injection/production) well pairs decreases oil production significantly. However, reducing the perforation length of both the injection and the production wells does not significantly decrease oil production rates. Changing the injection well design from a horizontal to a vertical orientation notably decreases oil production rates. Neither increasing the number of injection wells or the injection and production tubing size significantly increases oil production. Perforation length and tubing size influence the voidage replacement ratio and therefore should be considered during the various stages of heavy oil field development. Horizontal injection well designs are suited to rehabilitate the voidage replacement ratio (VRR) in depleted fields. The results also indicate that the temperature gradient increases with fewer horizontal injection wells (Case 1 versus Case 2), as well as when the horizontal injection well perforation section is reduced (Case 2 versus Case 3) and when a horizontal injection well design is substituted with a vertical injection well design (Case 6).Case 6 involves the most vertical injection wells and largest tubing size diameter.
Effect of CO2 Flooding During EOR Process on the Rock Petrophysical and Electrical Properties
Authors: Abdelgawad K. Z. , Mahmoud M. A.
Published: April 2013

During the life of a producing oil field several production stages are encountered. Initially, when the field is launched to production, oil flows naturally to the surface due to existing reservoir pressure in the primary phase. As reservoir pressure drops, water is typically injected to boost the pressure to displace the oil in the secondary phase. After water flooding the remaining oil can be recovered by a variety of means such as Carbon dioxide (CO2) injection, natural gas miscible injection, and steam recovery in the final tertiary or enhanced oil recovery (EOR) phase. CO2 has the capability of invading the zones that were unswept by water, as well as releasing and reducing trapped oil.

This paper discusses some of the experimental work that have been done in the literature and trying to connect it together to address the effect of CO2 flooding on the electrical properties of carbonate rocks and this paper will motivate the reader towards a new area of research that have not been fully covered. Knowing the change of rock electrical properties with the CO2 injection will enable the monitoring of CO2 front using electrical logging survey. This process can be used in EOR or storage in brine aquifers, the status of the reservoir can be determined through the monitoring of CO2 by seismic or electrical survey.
Cost-Effective Recovery of Bypassed Reserves Using Rigless Cement Packer Completion Technique: Case History from Offshore Egypt
Authors: Mahmood Amer , Maestrami Michele , Paoli Christiano , Waheed Arshad , D'Angelo Stefano , Repetto Carmen
Published: April 2013

In many Brownfield developments, toward the end of a well's life cycle, the primary production zone(s) commonly waters out or depletes, or the well sits idle with no alternative means of returning back to production. At this stage, as a normal course of action, the wells are re-evaluated for potential reserves that might have been bypassed during the original completion. For zones that do not appear promising or could be marginal in terms of delivery, the recompletion costs can be prohibitive. It is in such situations that "cement packer" completions performed rigless in offshore environments provide an economic alternative to workover operations. This technique can be cost-effective and has the potential to increase the producing life of a well.

This paper describes the successful application of a "cement packer" to recover bypassed reserves located above the production packer in an offshore field in the Mediterranean Sea. The technique allows zonal isolation between the various upper zones by placing cement slurry in the production tubing and casing annulus.

Conceptually, it might appear simple to perform such a job, but the planning and execution must be well formulated to ensure well integrity is maintained at all times. In this case history, the challenges of executing the job were examined from many different angles (i.e., high angle well, small platform, short weather window for operations, and multiple job sequences). The average cost was only 20 to 60% of conventional workover jobs, which is a savings of up to USD 400,000. The production results have also been encouraging. These successful results have revealed opportunities for reactivating many more shut-in wells with bypassed reserves that are currently considered economically marginal.
Establishing Higher Oil Production Capabilities: Engineered Approach Achieves Longest Lateral Hole Section in Kuwait
Authors: Al-Ajmi Hadi , Al-Barazi Nasser , Al-Rushoud Abdul-Aziz , Trivedi Ranjan , Maliekkal Harish , Ghoneim Osama , Saleh Mustafa , Nair Prakash
Published: April 2013

Kuwait Oil Company (KOC) is analyzing the feasibility of utilizing extended reach drilling to achieve a long lateral section to increase oil production in northern Kuwait. Several attempts were made to accomplish the objective with roller cone and PDC bits on various directional tools with limited success. The major problem was short bit life/cutting structure durability and steerability issues in the difficult Mauddud carbonate reservoir. A drilling optimization initiative would benefit the entire northern Arabian basin because Mauddud is an important oil reservoir with uniform thickness and extensive regional distribution.

Offset analysis showed three to four TCI bits were required to drill 3000 ft of lateral hole section. PDC bits display increased durability making up to 2500 ft of hole but were pulled for low ROP and unacceptable drilling inefficiency before reaching TD. A second PDC was required to finish the lateral and gain sufficient access to the reservoir. Before the optimization project, the longest single run with PDC was 2935 ft. The average footage drilled by roller cone TCI is approximately 1500 ft with average PDC footage around 2500 ft.

To improve PDC bit performance, a rock strength program was run to identify the unconfined compressive strength (UCS) of Mauddud for use in an FEA-based modeling system. The software pegged the formation's UCS range between 9-15 kpsi with peaks up to 24 kpsi. Analogous rock sample files were selected and laboratory tests were performed to duplicate fundamental shearing action under the appropriate confining pressures. The resulting data was entered into the modeling system and simulations were performed with a baseline PDC to identify how lithology influences the bit/BHA and to investigate was to mitigate destructive drillstring dynamics.

The engineering study produced a six-bladed PDC that drilled the longest lateral interval (5250 ft) in Kuwait through Mauddud. The bit displayed excellent steerability and completed the hole section without losing ROP. This resulted in 100% footage improvement against offset PDC runs and is more than 150% better than the best TCI performance. The completed well has provided a 200% increase in production capabilities making up to 4500 bbls/day.
New Material Balance Equation Allows for Separator Conditions Changes during Production History
Authors: Ibrahim Mohamed , Fahmy Mohamed , Salah Haitham , El-Sayed Mohamed , El-Banbi Ahmed H.
Published: April 2013

In field operations of volatile oil and gas condensate reservoirs, separator conditions often change because these volatile fluids are usually separated through three and more separation stages, when wellhead pressure allows. The well stream is usually rerouted to lower pressure separators at later stages of the field life.

Although the reservoir simulation is widely used for recoverable reserves calculations, material balance equation is still used as a fast and easy method for reserves and forecast calculations. The conventional material balance equation does not allow accurate calculations for hydrocarbons in-place when separator conditions change during the history of the field production, since PVT properties are usually calculated for specific separator conditions in black-oil and modified black-oil approaches.

In this work, a new material balance equation was developed. This equation can be easily used and will allow accurate calculations of hydrocarbons in-place when separator conditions change during the production history. The inputs to the equation can be easily obtained from the equation of state model (EOS) which is used to generate the black oil or modified black oil PVT tables. In some cases, PVT properties can be also calculated at different separator conditions using newly published correlations that take separator conditions into consideration.

To validate the new equation, many reservoir fluids covering a wide range of black and volatile oil reservoirs (and their associated PVT tables) were used. The new equation was applied to calculate oil in-place using the production and pressure data from many test cases generated by fully compositional simulation (note that compositional simulation takes into consideration the effects of changing separator conditions on production data during the simulation time). The new material balance was found to give results with close agreement to the compositional simulation model.
Real Accident Cost
Authors: Ibrahim Ashraf
Published: April 2013

An accident does not happen. It is always the direct result of someone somewhere sometime did something or failed to do something that was wrong or, some equipment for some reason did not work properly.

Whenever there is an accident there is a definite sequence of related factors.
Mastering the Risk Based Integrity Management Technique
Authors: Hegab Wael M.
Published: April 2013

This research is demonstrating the achievements done & benefits gained from developing the concept of maintaining Gasco's pipeline network from; implementing a prescriptive based approach of Inspection, Maintenance and Repair (IMR) in order, to a new trend was appearing & spreading through the pipeline operators all over the world which is Risk-Based approach within the framework of a Pipeline Integrity Management System (PIMS) which has also shown a cost effective approach.
Fishing for Talent: Strategies and Techniques for its Effective Management in Hydrocarbon Industry
Authors: Baskaran V. K. , Dani K. C. , Varyani S.. , Kumar K.. , Pokhriyal S. K. , Fernandez G. J.
Published: April 2013

Uncertainties that applicable to oil & gas sector are different in scale. Hazardous and commercially very important global parameters and the priority by individuals have changed due to enhanced communication, transport facility, social detachment due to human relationships. The patriotic definitions have changed with Joint Ventures (JVs). Last century the spiritual quotient was high, and the "z" axis growth was very high. The working spirit for the cause was very high. Recently the "x" axis (material) growth has changed the social texture, "Why not me" to "why me"?

The "y" axis growth with emotional quotient has played its role. High Emotional Quotient (EQ) people occupied higher positions. But to bind everybody and deliver requires High Spiritual Quotient (SQ). The uncertainties and social injustice can be superseded by evolving people.

Our oil industry developed more on "x" axis rather on "y" axis. This resulted in reduction on "z" axis growth. Some point's worth to be noted are 1.World Drama: All the employees have to play some defined roles and excel. 2. Same level working: The senior reporting to junior by age/date of joining/date of position holding has also has changed. The previous logics do not hold good. 3. Parts of same chain: All the workers are equal parts of the chain. One least important link can cause the disaster/ zero output. This needs to be addressed. 4. Z axis growth: This helps you to work for the organization even if you (apparently) feel the fruits are taken by somebody else. 5. Writing your own arc: work for your own satisfaction. 6. Part of family/staying together and 7.Counseling and gap addressing and will be discussed in the paper.
Guiding Drilling by Look Ahead Using Seismic and LWD Data
Authors: Esmersoy C.. , Ramirez A.. , Hannan A.. , Lu L.. , Teebenny S.. , Yang Y.. , Sayers C. M. , Parekh C.. , Woodward M.. , Osypov K.. , Yang S.. , Liu Y.. , Shih C.. , Hawthorn A.. , Cunnell C.. , Shady E.. , Zarkhidze A.. , Shabrawi A.. , Nessim M..
Published: April 2013

Seismic provides critical information for drilling, such as 3D structural images showing geological targets or hazards and formation properties relevant to drilling such as pore pressure. However, pre-drill estimates of formation pressures and structural depth images typically have large uncertainties. These uncertainties present drilling risks and could increase the cost of wells in the deepwater and other drilling environments. We present a new method that reduces the uncertainty up to large distances ahead of the bit by optimally integrating existing seismic data with new information acquired in real-time from the well being drilled.

Often the pre-drill seismic earth model remains mostly unchanged during drilling even though real-time LWD data contain significant new information about the formations being drilled. Real-time checkshot measurements provide constraints for the velocity model, real-time logs reveal formation tops, and other while-drilling information such as pressure measurements, mud weights, tests, and drilling events can be used to calibrate the earth model.

Recent advances in acquisition, processing, and integrated earth model building technologies have made this type of utilization of seismic and while-drilling well data to provide results in time for drilling decision making a reality. Results of two field tests are presented. First field work shows the ability of the technique to image a fault accurately in 3D space. The second field work demonstrates the ability to predict pore pressures up to 3000 ft ahead of the bit. Predicted pore pressures were within 0.25 ppg of the actual measured formation pressures.
Suitability of Eastern Gamagrass for In Situ Precipitation Catchment Forage Production in Playas
Authors: Gitz Dennis C. , Baker Jeffrey T. , Stout John E. , Brauer David K. , Lascano Robert J. , Velten Jeff P.
Published: April 2013

Freshwater playas, shallow ephemeral lakes whose basins fill after periods of prolonged or intense rainfall, occupy 3 to 5% of the land in the Llano Estacado and are considered marginal farmlands. The goals of this work were to determine if a native species, eastern gamagrass, could be grown on playa soils and to preliminarily evaluate the suitability of gamagrass [Tripsacum dactyloides (L.) L.] as a component of an in situ precipitation catchment forage production system. Flooding tolerance of gamagrass seeds was evaluated, and plants were grown on playa soil in both the greenhouse and field for several seasons. Gamagrass seed was resistant to extended flooding, especially at low ambient temperatures typically encountered in late fall or winter. Gamagrass roots penetrated nearly 2 m into waterlogged playa soil in greenhouse experiments. Stands were successfully established in playas, and plants survived for 6 yr when crowns were not destroyed by close mowing or vehicles. Eastern gamagrass is a viable candidate species that might be used as part of a novel playa‐based forage production system.
Bahiagrass Cultivar Response to Grazing Frequency with Limited Nitrogen Fertilization
Authors: Vendramini Joao M. B. , Sollenberger Lynn E. , Blount Ann R. , Aguiar Andre D. , Galzerano Leandro , Valente Andre L.S. , Alves Eveline , Custodio Leticia
Published: April 2013

Warm‐season grasses require N fertilization to achieve their full production potential; however, increased costs have limited the use of N by beef cattle (Bos spp.) producers. The objective of this study was to test the effects of two grazing frequencies (2 and 4 wk) on production, nutritive value, and persistence of ‘Argentine’ (tetraploid), ‘Pensacola’, ‘Tifton 9’, and ‘UF Riata’ (diploids) bahiagrass (Paspalum notatum Flügge) cultivars fertilized with 60 kg N ha–1 yr–1. The study was conducted in Ona, FL, from January 2010 to December 2011. Treatments were eight factorial combinations of two grazing frequencies (2 and 4 wk) and four bahiagrass cultivars. The four cultivars were grazed by beef cows (505±30 kg) for approximately 8 h to a 7.5‐cm stubble height at 2‐ or 4‐wk intervals. Diploid cultivars had greater herbage accumulation (HA) in the spring; however, Argentine had greater annual HA in 2010 and 2011. Plots grazed at 4 wk had approximately 50% greater HA than 2‐wk grazing frequency. Argentine and Pensacola had greater root and rhizome mass than Tifton 9 and UF Riata when grazed every 2 wk, while Argentine had greater cover than any of the diploids when grazed at the 2‐wk frequency. Results show that Argentine is a productive and persistent bahiagrass for beef cattle producers using limited N fertilization and frequent grazing in Florida. Decreasing grazing frequency is an effective management practice to increase bahiagrass HA and persistence, particular the upright‐growing Tifton 9 and UF Riata.
Multiple Herbicide Resistance in Wild Oat and Impacts on Physiology, Germinability, and Seed Production
Authors: Lehnhoff Erik A. , Keith Barbara K. , Dyer William E. , Peterson Robert K. , Menalled Fabian
Published: April 2013

The evolution of weed biotypes resistant to multiple herbicide modes of action, here termed multiple herbicide resistance, is a growing problem around the world. We investigated two multiple herbicide resistant (MHR) wild oat (Avena fatua L.) populations from Montana and hypothesized that they would exhibit fitness costs compared with two herbicide‐susceptible (HS) populations. Dose‐response tests showed that the MHR populations were resistant to difenzoquat (a membrane disruptor), imazamethabenz (an acetolactate synthase [ALS] inhibitor), flucarbazone (an ALS inhibitor), and tralkoxydim (an acetyl‐CoA carboxylase inhibitor). In greenhouse studies, we assessed differences between MHR and HS populations in seed germination, photosynthetic parameters, plant growth, and reproduction. Seeds of one HS population germinated more at cold temperature (4.9°C) and less at high temperature (29.6°C) compared with the other populations. Plants of this HS population also had lower stomatal conductance (23%), intercellular CO2 concentration (7.5%), and transpiration (15.3%) than the other populations, but there were no differences in photosynthetic rates between any populations. Also, there were no differences in relative growth rate among all HS and MHR populations. The MHR populations initiated seed production several days sooner than the HS populations; however, HS populations produced 67% more tillers, and one HS population ultimately produced 43% more seeds than the MHR populations, indicating a potential fitness cost of resistance. With the exception of seed production differences, our results do not indicate a consistent fitness cost. More research is needed in field settings and with resource competition to further evaluate fitness costs in MHR populations.
Nitrogen Input Effects on Herbage Accumulation and Presence of Pasture Plant Species
Authors: Guretzky John A. , Schacht Walter , Snell Laura , Soper Jonathan , Moore Stephanie , Watson Andrea , Klopfenstein Terry
Published: April 2013

Long‐term responses of pasture plant species to management strategies that vary amount and form of N inputs form a knowledge gap. Our objective was to determine how supplementation of grazing beef cattle (Bos taurus) with corn (Zea mays L.) dried distillers grains plus solubles (DDGS) in unfertilized pasture (SUPP) affects annual herbage accumulation and presence of plant species and functional groups relative to unsupplemented beef cattle on unfertilized (CONT) and N‐fertilized (FERT) smooth bromegrass (Bromus inermis Leyss.) pasture. We addressed this objective in the sixth (2010) and seventh (2011) years of a long‐term experiment in eastern Nebraska, where N input from DDGS supplementation and urea fertilizer averaged 0, 43, and 90 kg ha–1 yr–1 within CONT, SUPP, and FERT, respectively. For these years, annual herbage accumulation averaged 6.87, 6.80, and 10.58 Mg ha–1 (LSD = 1.49) and 66.5, 66.2, and 76.0% of herbage accumulated by 25 June (LSD = 5.3) in CONT, SUPP, and FERT, respectively. Smooth bromegrass occurred in 99.8% of 0.1‐m2 pasture quadrats regardless of treatment. Cessation of N fertilizer input, however, increased presence of annual foxtail (Setaria spp.), annual graminoids, and annuals among quadrats in CONT relative to FERT. Supplementation of DDGS, while shown in previous studies to improve weight gains and N use efficiency in cattle, supplied enough N through excretion to provide an intermediate level of resistance to annual weeds. Nitrogen excreted from cattle supplemented with DDGS, however, did not affect herbage accumulation in subsequent years.
Using Electro‐Magnetic Induction to Determine Soil Salinity and Sodicity in Turf Root Zones
Authors: Ganjegunte Girisha , Leinauer Bernhard , Schiavon Marco , Serena Matteo
Published: April 2013

The traditional method of determining electrical conductivity (ECe) and sodium adsorption ratio (SAR) from saturated paste is destructive and time consuming. The electromagnetic induction (EMI) method determines apparent electrical conductivity (ECa) and offers an alternative to traditional wet chemistry methods. This study evaluated the effects of 2 yr of subsurface‐drip and sprinkler irrigation with saline water on soil salinity and sodicity using both EMI technique and wet chemistry methods. Site specific calibration equations used to estimate ECe and SAR from ECa values were derived using a multiple linear regression (MLR) model included in the ECe sampling assessment and prediction model developed by the U.S. Salinity Laboratory. The ECe and SAR values were strongly correlated with ECa, with R2 ranging from 0.82 to 0.98. Both wet chemistry methods and EMI data indicated that salinity and sodicity values were greater in turf irrigated with saline water from a subsurface drip system compared to a sprinkler system. Salinity in the top 30 cm ranged from <1 dS m–1 in plots irrigated with potable water from both irrigation systems to 6.5 dS m–1 in plots irrigated with saline water from a subsurface drip system. Similarly, SAR ranged from <1 mmol1/2 L–1/2 in root zones irrigated with potable water regardless of the irrigation system, to >7 mmol1/2 L–1/2 when saline water was applied from the drip system. Study results indicated that the EMI technique provides accurate predictions of the spatial distribution of both salinity and sodicity in turf soils watered from differing irrigation systems and water qualities.