bluuebunny/crossref_metadata_2025_split huggingface dataset:
Planning Extended Reach Wells for Deep Water
Authors: Cunha J. C. , Martins A. L. , Sá C. H. M. , Fernandes P. Dore 
Published: December 2007

Abstract
Although Extended Reach Wells (ERW) have recently reached limits that would not even be dreamed a few years ago, most of those wells were drilled from onshore locations. Even though there are some experiences offshore, they are related to wells drilled on shallow waters from fixed platforms.
In Brazil, where the major oil field producers are located in deep waters, ERW may be in some cases the only technical and economical viable solution to the development of such fields. ERW, besides minimizing problems related to fluid flow, will also diminish the cost of development in large extension fields by reducing the number of production units per field. Also it may be the mandatory option in case of development of a large field by means of using a dry completion system (a TLP for example).
To drill ERW in deep water from a floating vessel such as a semi-submersible rig or a drill ship, is much more complex than performing the same job onshore. In Campos basin, Brazil, some of the problems that may be faced when drilling ERW in deep water fields are the presence of very unstable formations and small sedimentary coverage above the reservoir.
Due to studies indicating the feasibility of the use of ERW to develop oilfields in that basin, an R&D project was created aiming to develop techniques and operational procedures to be used when drilling those wells. Main tasks of the project were: –Well planning;–Wellbore stability;–Horizontal completion and sand control;–Drilling and completion fluids;–Cuttings transport.
This paper shows which methodology was used to manage the project and also some results and benefits obtained.
Foam Cementing Controls Deepwater Shallow Flow in the East Mediterranean
Authors: Waheed Arshad , Cockram Mark , Bahr Mahdy 
Published: December 2007

Abstract
Deepwater drilling, though relatively new in the Nile Delta region of the Eastern Mediterranean, has increased operating water depths to over 4,000 ft within a year from a record depth of 1,900 ft in the fall of 1999. The deepwater extension of the ancient Nile delta has been divided into six major operating licenses granted by the Egyptian government. This paper will primarily focus on the knowledge gained from experience by Rashpetco (JV between BG, Edison and Egyptian General Petroleum Company) in the West Delta Deep Marine (WDDM) development block (Fig. 1).
The WDDM is no exception to the common challenges encountered in deepwater projects around the world, including shallow gas and waterflow hazards.1,2 The obvious consequence of an unexpected shallow fluid flow is an uncontrolled blowout situation with no drilling-control equipment in place. In some reported cases, even after the flow was controlled prior to running casing, fluid flow occurred after cementing the surface pipe.
To date, the shallow flows witnessed in the WDDM have not resulted in any severe loss of capital, unlike other areas where the loss of wells and templates has occurred.3,4 Nor have shallow flows in the WDDM caused a safety threat to environment, personnel, or equipment; however, in some instances, they may have contributed to non-productive time in drilling operations. Nevertheless, efforts have been made to understand the flow mechanism and control these occurrences by developing shallow flow-control contingency plans and designing cement slurries suited to the challenges of deepwater cementing. Foam cement and other lightweight, high-strength cement slurries have been used to balance cement slurry weight between the low margins of the fracture gradients and the flow potentials of the drilled section. Foam cementing especially has been effective in many cases. This paper provides case histories in the control of unexpected shallow water flows and discusses the suitability of foam cement technology in deepwater situations.
Dynamic Simulation of Offshore Salt Zone Cementing Operations
Authors: Martins A. L. , Miranda C. R. , Santos F. J. P. , Bove A. 
Published: December 2007

Abstract
Salt zone cementing is still today a challenging issue. This paper presents an unique theoretical and experimental research project developed to support salt zone cementing operations in Campos basin, offshore Brazil. Theoretical approach includes the development of a numerical simulator which reproduces the mass transfer phenomena involved in the displacement of a cement slurry in front of a salt formation. The formulation is based on the solution of a well known diffusion-convection equation for the flow of a fluid through an annular section, being the external wall soluble. Experimental work includes the determination of salt mass transfer rates to cement slurries flowing through a large scale flow loop where the internal wall was formed by real halite cores. Mass transfer coefficients are then fed into the computer model.
The results obtained by running the simulator allow proper slurry composition design besides the definition of hydraulic parameters required for minimizing salt dissolution. Optimum salt compositions and adequate flow rates and regimes for pumping are recommended. Both formulation and experimental data are detailed. Charts of salt concentration profiles, as well as hole enlargement prediction are also provided.
Expanding the Range of Impregnated Technology: New Performance Benchmark Set in Middle East (Et Al)
Authors: Brackin Van , Isbell Matt , Christensen Hughes , Roggeveen Arent , Mohamed Mansouri , Wingate John , Welch Bob 
Published: December 2007

Abstract
The range of application of new diamond impregnated drill bit technology continues to expand into lithologies normally drilled with roller cone bits. Historically, application of impregnated drill bits has been restricted to deep intervals that contain mainly hard and abrasive sandstone. Conversely, PDC bits perform best in relatively softer, non-abrasive rock. This left a very common sequence of formations, hard abrasive sandstone interbedded with soft shale, to be drilled with either roller cone or PDC bits. None of the two choices has delivered satisfactory performance in terms of penetration rate and bit life.
Working with several operators, the bit company has conducted extensive laboratory and field development tests that have resulted in a new generation of aggressive diamond impregnated bits that offer unique advantages for drilling mixed formations more economically. The authors will outline the new impregnated technology in the context of its application and give examples on how to best apply it to achieve maximum performance. The following case studies will demonstrate significant performance improvement and illustrate an expanded range of applications for impregnated diamond bits.
Oman: 8-3/8" impregnated bit set new cumulative footage record of 1130 meters drilling in two fields in central Oman. Algeria, Rhourde Nouss field: Set longest bit run through Grés de Oued Saret to Quartzites de Hamra, drilling 97 meters further than best offset and replaced 2-4 bit runs. Algeria Hassi Messaoud field: Broke country single run footage record (361 meters); doubled footage over conventional impregnated technology while achieving the best penetration rate through the interval. Venezuela: Replaced three roller cones bits relative to hole section in offset wells.
Assessment of Salt Loading on Well Casings
Authors: Willson S. M. , Fossum A. F. , Fredrich J. T. 
Published: December 2007

Abstract
In the next decade significant new oil field developments will be brought on-stream in the deep water Gulf of Mexico. A large number of these wells will be drilled through salt. Assuring the integrity of these wells over the life of the field is a major drilling engineering challenge, as the consequences of well failures may result in billions of dollars remedial costs and lost production.
To address these challenges for BP's deepwater developments, advanced numerical finite element analyses of salt / casing interaction were undertaken by Sandia National Laboratories using state-of-the-art computational modeling developed as part of extensive research supporting the Strategic Petroleum Reserve (SPR) and the Waste Isolation Pilot Plant (WIPP) projects.
The paper summarizes, briefly, the salient features of salt mechanical behavior of relevance to well integrity. The results of numerical modeling of casing loading are presented which focus on the importance of assessing the possibility of both uniform and non-uniform loading by the salt; and the impact that production-induced heating of the salt has on the rate and magnitude of casing loading.
Based on the findings of these analyses, strategies for minimizing the magnitude of loading on well casings are discussed. The relative merits of cementing the annulus through salt are compared with the option of leaving the annulus open in order to defer the time at which salt loading occurs.
A "Standardized" Method for Ranking of Scale Dissolver Efficiency. A Case Study from the Heidrun Field
Authors: Kotlar Hans Kr. , Selle Olav M. , Haavind Frode 
Published: December 2007

Abstract
A new and simple, "standardized" method was developed in order to rank efficiency of various scale dissolvers. Five different scale dissolver products were compared for performance at Heidrun related conditions with regards to their dissolving capacity and dissolution rate/kinetics (initial speed performance) on genuine field scale samples from well A-28, Heidrun.
The overall treatment and shut-in time might be considered an important factor in remediation procedures. By comparing the performance curves of the dissolvers, the product giving the highest initial dissolution kinetics could be chosen. Moreover, there are other factors that also will influence the choice of the best-suited product, like dissolution rate of contaminated field scale, cleaning procedures, environmental rating, and total dissolution capacity.
The effects of oil contamination and cleaning procedures, involving mutual solvent or surfactants, were studied. The different products varied in active cleansing power and in sensitivity for available "active" surface area, as they will contain more or less surface-active co-agents.
In complex scale compositions, typical to most field situations, the dissolution of one particular scale species could be rate limiting to the overall process. Temperature and concentration effects could also be investigated in this set up.
By implementing this new ranking method, three chemicals were given a technical qualification for use at Heidrun. So far two of the products have been field-tested. The test procedure and a comparison to the field performance in the Heidrun cases, will be presented.
Interplay of Phase Behavior and Numerical Dispersion in Finite Difference Compositional Simulation
Authors: Jessen Kristian , Stenby Erling H. , Orr Franklin M. 
Published: December 2007

Abstract
Compositional simulation of multicontact miscible (or near-miscible) gas injection problems is typically performed using numerical finite difference (FD) schemes. Such simulations are intrinsically affected by numerical dispersion. In this paper we propose a method to assess the sensitivity of a particular displacement calculation to the effects of numerical dispersion, for systems with realistic multicomponent fluid descriptions. We use two simple ternary systems to illustrate how dispersion and convection interact to determine displacement composition paths and to define a "dispersive distance". We show how the dispersive distance relates to displacement performance with a detailed analysis of grid size effects on the recovery predictions for 1D displacements of a CH4 – C4 – C10 system by pure N2 and mixtures of N2 and CH4. We then show that the sensitivity of multicomponent compositional simulations also correlates well with the dispersive distance. We demonstrate that quantitative difference between oil recovery predicted by coarse grid numerical simulations and values obtained from analytical solutions to the conservation equations, can be estimated well from calculating the distance between the dilution line and the composition path predicted by the method of characteristics. Finally, we apply the assessment of sensitivity to 2D displacements in a heterogeneous porous medium to demonstrate the interplay of phase behavior, adverse mobility and numerical dispersion.
Scaling of Spontaneous Imbibition in Gas-Liquid-Rock Systems
Authors: Li Kewen , Horne Roland N. 
Published: December 2007

Abstract
A method has been developed to scale the experimental data of spontaneous water imbibition (cocurrent) for gas-liquid-rock systems. In this method, a dimensionless time has been defined with the effects of relative permeability, wettability, and gravity included. The definition was not empirical but based on a theoretical derivation. Using this dimensionless time, experimental data from spontaneous water imbibition in different rocks with different size, porosity, permeability, initial water saturation, interfacial tension, and wettability might be scaled. The scaling model proposed in this study for gas-liquid-rock systems was verified experimentally for different rocks (Berea, chalk, and graywacke from The Geysers) with significantly different properties; it was also verified experimentally at different initial water saturations in the same rock. The scaling results from this study demonstrated that the cocurrent spontaneous water imbibition in gas-liquid-rock systems could be scaled and predicted.
A Successful Field Test of Microbial EOR Process in Fuyu Oilfield, China
Authors: Nagase K. , Zhang S. T. , Asami H. , Yazawa N. , Fujiwara K. , Enomoto H. , Hong C. X. , Liang C. X. 
Published: December 2007

Abstract
This field test for Microbial EOR (MEOR) has been carried out in Fuyu oilfield, China since 19961,2. Waterflooding by a patterned flood has been applied for over 20 years and various measures to decrease high water cut has been discussed for long time.
The objectives of this MEOR project are to increase oil production from a water-flooded reservoir and to evaluate ability of microorganism (CJF-002) screened in our study. CJF-002 has an ability of producing insoluble polymer metabolically feeding on nutrient. This metabolic process is considered to be useful on plugging high permeable zones to reduce water channeling.
Prior to the injection test of CJF-002 into the reservoir, core-flooding tests were carried out in order to evaluate the magnitude of permeability reduction due to plugging by the insoluble polymer. In the field tests, the following three different approaches were conducted: –Huff-n-puff test (single cycle) at production wells (1999),–First microbial treatment at injection wells (2000), and–Modified microbial treatment at injection wells (2001).
In huff-n-puff test, CJF-002 and molasses were injected into 6 production wells. Among them, 4 wells indicated oil production increase and water cut decrease4,5. Based on these positive results of huff-n-puff test, the first microbial treatments were conducted at injection wells. In these treatments, cell count of CJF-002 and concentration of insoluble polymer were measured at the injection manifold and production wells to evaluate the metabolic activity of CJF-002 by colony forming unit (CFU) method and HPLC. Moreover, well logging such as Reservoir Saturation Tool (RST) and Water Flow Logging (WFL) and tracer tests were conducted before and after the microbial treatment to evaluate the effect of insoluble polymer on injection profile modification. As a result, microbial propagation was observed, however, the effect of injection profile modification has not been developed. The major reason was considered to be that sufficient propagation of CJF-002 was prevented by predominant population of other microbes propagated in the injection pipeline. From the unsuccessful result in 2000, injection method of CJF-002 and molasses was modified to prevent a propagation of other microbes and the modified microbial treatment was carried out in 2001. As a result, oil production in the test area increased more than twice in volume and the effect of plugging the high permeable zones was suspected from the results of tracer tests and preliminary reservoir simulation study.
Coal Well Decline Behavior and Drainage Areas: Theory and Practice
Authors: Seidle John P. 
Published: December 2007

Abstract
Although early gas and water production rates from a coal well are often erratic, at late time these wells typically exhibit gentle declines in both gas and water. A literature review indicated time transfoms for conventional gas well decline analysis may or may not be applicable as coal wells often show exponential declines when plotted in real time. A theoretical gas decline coefficient was derived from the pressure-squared form of Darcy's Law and the Z∗ formulation of the mass balance equation. Conditions necessary for exponential decline are discussed. A theoretical water decline coefficient was developed by coupling a water mass balance equation with an expression for Estimated Ultimate Recovery. Calculated decline coefficients are compared with reported and simulated declines in the Warrior, Powder River, and San Juan basins. Reasons for differences, as well as agreements, between theoretical and actual decline coefficients and drainage areas are discussed. Practical applications of these results include prediction of the gas decline coefficient from coalbed parameters, calculation of drainage area from water decline behavior, and estimation of total water volumes to be disposed.
Successfully Pushing the Limits in Tight Gas Fracturing
Authors: Pearce K. W. , Heiken K. , Samuelson M. L. , Mueller F. , McConnell S. B. 
Published: December 2007

Abstract
In the past year, an optimization process has been pursued to improve production from South Texas tight gas fields. During this period an engineering study was conducted on the fracturing design process, the fracture parameters and fluids being used. From this study, several design changes to the fracture stimulation program were made to improve the created geometry and hence increase the production.
Progress has been made to improve conductivity, effective fracture length and production response from tight gas fracturing in South Texas. The progress is due to a combination of better job designs, more consistent fracture treatment placement and novel fluid chemistry. This paper discusses the design parameters necessary to ensure consistent job results for tight gas reservoirs. Results presented are from comparisons of quantitative field data based production analysis.
Advanced Open Hole Multilaterals
Authors: Durst Doug G. , Hart Shane P. , Brown W. H. Sonny 
Published: December 2007

Abstract
Stimulating oil production from Algeria's Hassi Messaoud oil field has proven to be a difficult proposition. Sonatrach is now achieving substantial production increases from non-producing assets with an aggressive re-entry well program. The key to success is a combination of new technologies. Some 600 of the vertically drilled wells are candidates for reentry and rework to drill horizontal laterals, however to be eligible they must meet the following basic criteria which Sonatrach have established: They must be open hole completions.They must have been shut in for a long time – effectively since being drilled.
The zone of interest is the Upper Cambrian, an extremely hard and abrasive sandstone and quartzite formation that are extremely difficult to drill. Kicking off laterals in these re-entry wells is therefore challenging and required the development of new tools in order to do so effectively. Additional challenges were posed by the requirements to be able to isolate the laterals, tie them back to the original cased hole and provide for thru tubing re-entry capabilities.
This paper addresses the milling, drilling and completion issues relevant to these wells and discusses the solutions arrived at. Using a typical well re-entry case history, it details the steps taken to create a TAML1 level 1 open hole multilateral (or a psuedo type level 3 with mechanical integrity) combined with either through tubing completion or conventional tubular completion. It will describe how a combination of liner hanger and inflatable packer technology, together with a large bore completion allowing for selective thru tubing re-entry, has led to several successful installations. Future installations will consist of level 3 multilateral junction hardware that will be utilized to provide formation support and simpler reentry and where required the addition of lateral isolation to cut off gas encroachment. An extensive gas injection program (and in some cases water injection) is utilized in the field to assist in production recovery. The use of annular casing packers in conjunction with liner or tubular plugs will allow for isolation shutoff of either lateral at some later date when gas or water influx offsets oil production gain.
Field Experience with Applying Foamed Cement Slurries in Mature Depleted Formations
Authors: Spoerker H. F. , Doschek M. 
Published: December 2007

Abstract
Primary cementing of production casings across multiple, mature and severely depleted reservoir horizonts represents a significant challenge vis a vis light weight cement slurries exhibiting adequate compressive strengths at reasonable cost. The paper presents experience gained with introducing the application of nitrogen-foamed cement slurries with specific gravity as low as 1.34 SG on primary cementing jobs of gas formations in the Vienna Basin, both technically as well as psychologically. Initial obstacles – both from a managerial and engineering standpoint – are presented, and ultra-sonic cement evaluation logs of the first jobs are discussed together with job problems and their representation on the logs.
Advanced Steerable Drilling System Raises Performance to New Levels
Authors: Wong Thomas , Dirksen Ron , Gaynor Tom , Chen David C-K. , Chong Adrian C. , Si-Boon Wee 
Published: December 2007

Abstract
Conventional positive displacement motors (PDM's) are widely used in most directional drilling jobs. Polycrystalline diamond compact (PDC) bits are often used with the PDM's because of their longer life and increased rate of penetration (ROP). But PDM's used with conventional PDC bits often create hole problems and high vibrations that result in stuck pipe, casing running problems, downhole equipment failure, and lost drilling time. A new steerable assembly has been designed with an extended gauge bit and matched motor. The main objectives are to improve hole quality, reduce vibrations, and increase ROP. This paper will describe the working principles of the new system and how it has performed for Sarawak Shell Berhad and Sabah Shell Petroleum Company (SSB/SSPC) wells in offshore Malaysia.
A Study Reveals: Gravity and Carelessness are #1 Causes of Accidents
Authors: Buettner Kurt , Kinzel Holger , Pichl Wolfgang 
Published: December 2007

Abstract
The analysis of accidents over the past 20 years reveals the reasons why accidents happen and give valuable indications on how to prevent accidents in the future.
In a 20 year history, collection and evaluation of accidents which happened to employees of Weatherford Oil Tool GmbH, Germany, depending on the German legislation only "Lost Time Accidents" are recorded. "Non Lost Time" - and "Near Miss Incidents" will be mentioned at the end of this study.
Our goal is of course to reduce the number of accidents to zero. The way will still be difficult, steep and slippery but many reasons count to make our utmost efforts to achieve that goal.