bluuebunny/crossref_metadata_2025_split huggingface dataset:
Phosphonic Acid Complex for Stimulating HF-Sensitive Reservoirs – A Revolutionary Response
Authors: Nwoke Linus , Uchendu Chike , Arukhe James , Essel Philippe , Ndinemenu Felix , Vecchio Alessandra , Fatusin Sylvester 
Published: December 2007

Abstract
HF-sensitive reservoirs that could not be hydraulically fractured nor effectively stimulated have been a challenge to the Petroleum Industry, hence locking the potential reserves that could otherwise be producible. These formations are typically those with high swelling clays, chlorite clays, feldspars and certain zeolites. Experience shows that even when such formations are stimulated with conventional HF- or HCl-based acid systems, the production performance declines shortly after the treatments, causing the reservoirs to produce at less-than-optimum rates. The skin damage associated with such reservoirs and stimulation by-products act as down-hole chokes, strangling production and increase drawdown.
Successful stimulation of these kinds of HF-sensitive reservoirs had been carried out with a Organo-Phosphonic Acid Complex. Treatments have been carried out in seven Oil Producers, Water Injectors and Gas Injection wells in the Niger-Delta Nigeria and an oil producer in South East Asia. Post-treatment rates were above 800% of the pre-treatment values and more than 100% the maximum potentials ever recorded by most of these wells since they were commissioned. The new acid system offered true stimulation of carbonate and sandstone reservoirs as well as restoration to natural permeabilities of these intervals by the process of sequestration and complexation. An overall dramatic response of more than 200% over the wells treated with other formulations in the same basin was achieved.
This paper discusses the non-HF based Organo-phosphonic acid formulations for Oil Producers, Gas Producers, Water Injectors and Gas Injection wells in both carbonate and sandstone reservoirs. The process of dissolution of the acid soluble and insoluble minerals that plug the near-wellbore region; candidate selection criteria; design; process of scale inhibition; field applications; results; treatment effectiveness and evaluations. The performance over other formulations is compared with respect to treatment costs, accelerated production, payback time, sustained production or Injectivity after treatment and percentage of original permeabilities being restored.
Capillary Number in Heavy Oil Solution Gas Drive and Its Relationship with Gas-Oil Relative Permeability Curves
Authors: Ostos A. , Maini B. 
Published: December 2007

Abstract
Many heavy oil reservoirs under solution gas drive show a significant increase in productivity. Different mechanisms have been postulated to explain the high recovery factors observed in the field. Lately, a widely accepted cause of this increase in productivity is the foamy oil flow, which dramatically decreases the gas relative permeability. However, it still remains inadequately understood.
It has been reported that the foamy flow effects observed in the laboratory depletion tests are strongly affected by depletion rate. This observed rate effect has been attributed to the influence of the pressure depletion rate on bubble nucleation. However, the researchers have mostly overlooked the capillary number, which increases significantly with increasing depletion rate. The goal of this study was to examine this capillary number effect in heavy oil reservoirs and its relationship with gas-oil relative permeability curves.
A number of experiments were carried out on a two-meter long sand-pack to determine the conditions required to produced more oil under solution gas drive. The experimental data were matched on a commercial black oil simulator to determine the relative permeability curve under varying flow conditions and at different capillary number. The experimental results show that the oil produced was a unique function of capillary number and beyond a critical capillary number no additional improvement in the recovery factor was observed. An examination of the changes of capillary number during the test provides insight into the gas-phase build up during solution gas drive and the resulting production behavior. It was also found that oil relative permeability increases and gas relative permeability decreases with increasing capillary number. At high capillary number, relative permeability ratio remains very low up to higher value of gas saturation. The results from this research suggest that the conventional correlations of gas-oil relative permeability should incorporate the effect of capillary number in order to improve the prediction of foamy oil flow mechanism.
Comparison of Non-Darcy Flow of CO2 and N2 in a Carbonate Rock
Authors: Grigg Reid B. , Zeng Zhengwen , Bethapudi Laxman V. 
Published: December 2007

Abstract
This work presents the non-Darcy behavior results of carbon dioxide (CO2) compared to the previous work using nitrogen (N2) and is based on 85 series of high-velocity gas flooding experiments under high-pressure and high-temperature. It was found that pore pressure has more influence on permeability in CO2 flooding than that in N2 flooding. In contrast, temperature has definite and consistent influence on both permeability and non-Darcy flow coefficient in N2 flooding, but the same influence in CO2 flooding was not observed. Mechanism behind these differences is attributed to physical property differences of the two gases. Much of the work was near the CO2 critical point or liquid regions. Other anomalies are attributed to thermal effects caused by expansion cooling of the CO2. Field data indicates that this phenomenon could be responsible for productivity loses in high flow rate CO2 wells. Accordingly, attention should be paid to avoid flowing CO2 at conditions near its critical point.
Underbalanced Techniques to Reduce Drilling Hazards of Loss of Circulation and Underground Flows
Authors: Abel L. William , Yarim Gokhan 
Published: December 2007

Abstract
This paper discusses underbalanced drilling planning, implementation and risk management to solve a drilling hazard where a weak upper formation is open to a lower high pressure gas reservoir that has pore pressure greater than the frac gradient of the weak formation. The problem has been solved in the Burgos Basin where loss of circulation and underground blowouts are a major hazard for drilling operations. The paper presents the planning process, risk assessment/HAZOP analysis, computer modeling with a steady state 2-phase flow model, equipment specifications, operational guidelines and field results from an underbalanced operation undertaken in August 2003 to successfully drill a well where there was a continual inflow while a weak lost circulation zone was exposed.
Re-enterable Through-Tubing Gravel-Pack System
Authors: Leising L. J. , Ali A. M. , Young J. R. , Arciniegas O. E. 
Published: December 2007

Abstract
The use of through-tubing gravel packs (TTGPs) has been limited in the past to low-flow-rate systems that are not suitable for frac packing or vent-screen systems that use a long annular pack of sand for pressure isolation. Vent-screen installations are increasing rapidly—in both new completions and for remedial work—because of the ability to develop longer fractures and increase permeability with high-rate frac packs. Unfortunately, vent screens have a high rate of failure because of the lack of positive pressure isolation.
This paper presents a new re-enterable-screen method that allows a high-rate frac pack with positive pressure isolation either through an inflatable packer or packoff to the tubing.
Transient Simulator-Based Training of Rig-Site Decision Makers and Rig Crews for Through-Tubing Coiled Tubing Underbalanced Multilateral Project
Authors: Frink P. J. , Leslie C. , Wooten J. E. 
Published: December 2007

Abstract
Introduction
The Sajaa Gas field, producing from the Thamama carbonate formation, is a prolific and important gas producing field for BP-Sharjah and its partners in Sharjah, United Arab Emirates.1
In December 2002, BP-Sharjah decided to embark on a through tubing coiled tubing UBD campaign to drill underbalanced, horizontal multilateral sidetracks to increase wellbore deliverability in this low pressure environment.2
Due to the probability of cross-flow between multilateral legs due to variations in reservoir pressure and the existence of high intensity fractures, maintaining dynamic pressure control presented a significant technical challenge. Safely detecting and responding to rapid changes in a complex well geometry with a very small volume well annulus was of paramount importance. Adequate crew training and effective communication between rigsite decision-makers was considered to be essential success pre-requisites for conducting safe operations.
Hard Scale Mechanical Removal: A Solution for Brazilian Offshore Operations
Authors: Quiroga M. H. V. , Calmeto J. C. N. , Pinto S. L. , Assis C. A. S. , Santos I. 
Published: December 2007

Abstract
Scale deposition in producing well bores is becoming a serious problem to the oil industry. In situations of injected seawater breakthrough, the problem is especially hard, since the growth is often Barium or Strontium Sulfate, both of which almost completely insoluble.
The initial scale growth will change the surface roughness in the production tubing, raising the frictional pressure drop and reducing the production rate. Further growth will decrease the flowing area and hinder the production. Ultimately the scale can restrict the production tubing sufficiently to prevent access for tools into the lower sections of the well and finally it can bridge over completely.
The range of options for scale removal goes from a simple brush run using slick line or basic chemical treatment up to a full rig workover to replace the production string. Very often through-tubing treatments using coiled tubing are used due to the savings compared to the rig cost. This technology can convey tools for mechanical scale removal and also works as a fluid conduit for chemical treatments.
The objective of this paper is to describe the coiled tubing abrasive jet technology used to successfully clean, for the first time, heavy affected Barium Sulfate scale in production tubing in Brazilian offshore operations and its impact on the well economics.
Optimizing Integrated Rigless Plug and Abandonment – A 60 Well Case Study
Authors: Tettero Frans , Barclay Ian , Staal Timo 
Published: December 2007

Abstract
This paper presents the Petroleum Development of Oman (PDO) Rigless plug and abandonment (P&A) methodology, technologies & practices which resulted from the corporate goal to find a cost effective means to P&A obsolete oil wells. As the main Omani Oil Exploration & Development company, PDO is abandoning aging wells and fields and they must balance environmental and financial objectives. Technically sound abandonment practices are essential for long-term environmental protection. Many operators are revising their P&A procedures to ensure that abandoned reservoirs remain permanently sealed. During this 60 well pilot project PDO optimized their P&A practices by employing a rigless methodology as well as new technologies to minimize the cost of abandonment while still ensuring long term environmental protection from once prolific oil wells. Using a Coiled Tubing unit and eliminating the need for a rig can help speed up operations and reduce costs, while at the same time safeguarding environmental concerns. Typical savings of 30% over previous abandonment campaigns with a drilling rig have been achieved by PDO. This constituted a total saving of over $5M for this 60 well campaign.
Managed Pressure Drilling with the ECD Reduction Tool
Authors: Bern P. A. , Armagost W. K. , Bansal R. K. 
Published: December 2007

Abstract
High equivalent circulation density (ECD) is responsible for many wellbore pressure-related problems during drilling. Proper wellbore pressure management is a critical part of normal drilling practices, where static and dynamic fluid pressures are used to contain formation pressures and assure wellbore stability. Excessive fluid pressure while circulating can create problems including reduced operating margins between fracture and pore pressures and, in the extreme, lost circulation. To address these problems, an ECD Reduction Tool (ECD RT) is being developed.
The ECD RT is designed to counter downhole pressure increase due to friction in the annulus by reducing the hydrostatic head. The tool is expected to have a broad range of drilling applications including the narrow pore/fracture pressure margin in the deepwater environment, wellbores prone to instability, pressure depleted reservoirs and extended reach wells. The ECD RT will also potentially reduce the impact of uncertainty when selecting casing setting depth by widening the usable margin between pore pressure and fracture gradient.
Building a Vietnamese Company
Authors: Deaves Craig 
Published: December 2007

Abstract
This paper describes the strategy BP developed and the processes it used to build its Upstream Operation in Vietnam. This strategy followed a simple 3 point plan which covered recruitment, training and assessment through to retention. It describes the processes used to develop competency and provide assurance that BP has the right people with the right skills in the right place at the right time – both now and in the future.
The facilities include the Lan Tay offshore gas platform, the Dinh Co Terminal and the Phu My 3 Power Station. BP has recruited and trained over 250 technicians and support staff over the past 3 years to commission, operate and maintain these facilities.
Gravel Packing Wells Drilled With Oil-Based Fluids: A Critical Review of Current Practices and Recommendations for Future Applications
Authors: Parlar M. , Twynam A. J. , Newberry P. , Bennett C. , Elliott F. , Powers B. , Hall K. , Svoboda C. , Rezende J. , Rodet V. , Edment B. 
Published: December 2007

Abstract
Many of the recently discovered reservoirs in deep-water/subsea environments are prime candidates for horizontal open-hole gravel packs. Presence of multiple reactive shale breaks and penetration of different sand bodies along these holes introduce a formidable challenge for selection of proper carrier fluids, considering that most of these wells require oil-based (OB) drilling fluids.
Various procedures were practiced for gravel-packing wells drilled with OB fluids, most utilizing water-based (WB) carrier fluids. Primary concern in using WB carrier fluids is the destabilization of the shales.
If the displacements to WB fluids are performed prior to running in hole with the sandface completion assembly, inability to run the screen assembly to target zone is the risk. Consequently, operators were forced to use a two-step process, whereby a predrilled liner is run in hole in OB fluid environment, followed by displacements to WB fluids and gravel-packing with WB fluids. This approach introduces additional rig time and increases completion costs.
If the displacements to WB fluids are performed after running in hole with completion assembly, primary challenge is the prevention of screen plugging. This necessitates a comparison of the benefits and risks of displacements to solids-free oil-based fluids and conditioning of the OB drilling fluid, considering logistics.
An additional consideration in gravel packing with WB fluids in reactive-shale environments is the risk of intermixing of gravel with shales, thus reduced gravel-pack permeability. Various approaches may be taken to minimize this risk. The type of carrier fluid must also be kept in mind from a formation and gravel pack damage standpoints, should losses be experienced during gravel packing.
Another approach in reactive shale environments is to use an oil-based carrier fluid and avoid exposure of the open hole to WB fluids both prior to and during gravel packing. This approach, practiced in two applications, also has its limitations.
In this paper, a critical review of gravel-packing practices in oil-based drilling environments is provided, along with some of the recent developments and recommendations for future applications based on lessons learned from earlier practices.
A Novel Approach to Production Logging in Multiphase Horizontal Wells
Authors: Vu-Hoang D. , Faur M. , Marcus R. , Cadenhead J. , Besse F. , Haus J. , Di-Pierro Esteban , Wadjiri Abdoulaye , Gabon Perenco , Hofmann Andreas 
Published: December 2007

Abstract
Production logging sensors based on center-point measurements are not always successful in obtaining accurate flow profiles in triphase horizontal wells because of the effects of factors particular to these wells: fluid segregation, small changes in the well inclination, and the flow regime.
This paper presents a new tool designed specifically for highly deviated and near to completely horizontal wells. The tool provides a recording of holdup and velocity profiles along the vertical diameter of the borehole cross-section. Three sensor arrays consisting of six optical probes, six electrical probes, and five spinners are spread across the well bore on retractable arms that can be opened and closed with a hydraulic sub to better locate holdup interfaces. The optical probes use the fluid's reflectance to derive the gas holdup, and the electrical probes measure the fluid's impedance to derive the water holdup. The spatial location of the different sensors is accurately known through the use of an integrated relativebearing sensor and a caliper measurement. The direct measurement of the velocity and fluid holdup profile enhances the capability of the analyst to determine the downhole phase split and reduces the uncertainties associated with triphase flow interpretation.
This paper will discuss the problems mentioned and will illustrate through worldwide field examples the success of the new tool.
Production of Waxy Low Temperature Wells with Hot Gas Lift
Authors: Fleyfel F. , Meng W. , Hernandez O. 
Published: December 2007

Abstract
An Oil reserve is discovered in a remote shallow water area offshore Africa, where the water depth is approximately 200 ft. The predicted production rate is approximately 500 BPD per well. The obtained oil samples indicate that the produced fluid has a high pour point (91°F) and a high wax appearance temperature (105°F). A dry tree completion is the planned option for this field. The wellhead flowing temperature (WHFT) is predicted to be below the wax appearance temperature (WAT) during normal flow without heating.
Under certain specific field conditions, such as the development being considered, hot gas can be used as a means to maintain WHFT above the oil WAT and also be used as an artificial lift method to produce the low pressure / low temperature wells (LPLT). Economically, since the reserve is located remotely from gas market, the produced gas is "free." This paper describes the engineering evaluation of a hot gas lift design concept for a particular LPLT field. The hot gas lift method will avoid wax deposition, gelling and blockage problems in the wellbore. The wellbore thermal-hydraulic behavior is studied to optimize gas lift injection rates and temperature.
Water Permeability Reduction Under Flow-Induced Polymer Adsorption
Authors: Ogunberu A. L. , Asghari K. 
Published: December 2007

Proposal
The influence of induced polymer adsorption for reducing the effective permeability to water in reservoirs was investigated. Results for the anionic polymer used in this study, show that polymer adsorption is unaffected by the ionic character of polymers, provided the polymer is hydrophilic.
In this paper, we present experimental results that show at increased shear rates, there is improvement in the adsorbed polymer layer. This phenomenon is known as flow-induced adsorption. These experiments indicate that above a critical shear rate, there is a shift in permeability-reduction-mechanism from static to flow-induced adsorption, necessitating a sharp increase in adsorbed polymer layer.
Different scenarios to investigate the effect of polymer residence time and increasing rate of brine flush were investigated. Results show that there is a marked difference on water permeability reduction at zero polymer residence time and when a polymer residence time is allowed. Under static adsorption, slight increase in adsorbed layer thickness at low shear rates is observed. This effect is induced during brine flush when polymer macromolecules are forced to penetrate the existing adsorbed polymer layer. This results in maximum conformance of the polymer macromolecules at low shear rates, contributing significantly to the influence of flow-induced adsorption, depending on the rate of brine flow. All the experimental results revealed that the critical shear rate for this polymer is between 400 to 500 s-1 in the absence of mechanical degradation. For comparison with the above experimental results, similar experiments were performed at increased polymer concentration and also carried out in a core. Results indicate that the permeability-reduction-mechanism is constrained by increased polymer concentration and low-permeability porous media.
Drilling Metrics for Improved Casing Running Performance
Authors: Mason Colin J. , Chen David C-K 
Published: December 2007

Abstract
Despite the use of advanced rotary steerable systems to improve drilling capability and performance, casing running in these same wellbores can sometimes be unpredictable. A collaborative study has been undertaken to develop a set of drilling metrics to assist with identifying wells where casing running has a risk of failure. This project called "DMICRP" (Drilling Metrics for Improved Casing Running Performance) is currently in the early phase of development; and, therefore, results presented here reflect thoughts, ideas, and progress to date. The framework described in this paper is not only specific to running casing and liner but can also be applied to the installation of other tubulars such as solid expandable tubulars and expandable sand screens. The project is also seeking collaboration with other operators and interested parties to share data and experience. Upon completion of the project, the knowledge based system will be made available to the drilling community.
Information System Optimization for Operations
Authors: Dumont Jacques , Duzan Marie-Christine , Huard Gérard 
Published: December 2007

Abstract
After the period of merger between TotalFina and Elf and the multiplication of complex operations, it has become imperative for TOTAL to optimize its Information System for operations management by taking advantage of the outstanding improvement of the Information Technology.
The main objective was to ensure an optimal environment of IS tools to end users and management in term of front office, engineering software's, data management, documentation, infrastructure and organization. The ultimate goal remains to vastly improve the costs of the Information System, the technical knowledge of engineers, the field experience sharing and finally the quality and efficiency of Operations.
This paper describes the strategy, information technology, technical applications and process used to address the optimization of an efficient and adapted Information System for Operation Management. This concerns Drilling, Completion, Production, Technology and Project activities.
This paper will also describe the specific solutions adopted for each activity as well as the problem encountered and lessons learned. It will then discuss the key factors of success, potential risks and associated costs.