bluuebunny/crossref_metadata_2025_split huggingface dataset:
Technology for Controlling Eccentric Wear of Sucker Rods and Tubing in Pumping Wells Lifting Fluids Containing Polymer
Authors: Wang Yan , Wang Demin , Sun Zhi , Han Hongsheng , Gong Mingjing , Wang Gang 
Published: December 2007

Abstract
In Daqing Oil Field, after polymer flooding, severe eccentric wear of sucker rods and tubing in many wells with pumping units have occurred. The life span of the tubing string has decreased from 750 days for lifting fluid that does not contain polymer to 270 days for fluid that contains polymer. This has greatly increased work-over job frequencies and the production cost, and has seriously affected normal crude oil production.
With respect to this problem, this paper gives an introduction to a technology to control eccentric wear of sucker rods and tubing in pumping wells lifting fluid containing polymer.
Based on visco-elastic fluid dynamics, the constitutive equation of visco-elastic fluid and its flowing equation in an eccentric annulus is established, the magnitude of the normal force caused by the flow of fluid containing polymer on the sucker rods and pump barrel is derived and calculated. Based on lab experiments with visco-elastic fluid flowing in the annulus formed by the tubing and sucker rod, the relationship between the magnitude of the normal force of flowing viscoelastic fluid with different concentration, velocity and eccentricity of the sucker rod related to the tubing is measured; the resistant force of visco-elastic fluid flowing across pump valves and pump barrels is also measured; it could be seen (both visually and numerically) that the eccentric wear is mainly caused by the normal force of the flowing visco-elastic fluid.
On the basis of the above study, measures to prevent eccentric wear were implemented, which includes centralizing sucker rods, using large clearance pumps with large channels, using uniform diameter sucker rods in the whole well-bore and regularly rotating the sucker rod string. Practice on 6,266 wells in the field indicates that these measures can effectively solve the problem of eccentric wear of sucker rods and tubing in pumping wells, the life span of the tubing string increased from 270 days to more than 1,000 days, which brought about marked economic benefits. At present, all pumping wells in Daqing that lift fluid containing polymer use the technology described in this paper.
Practical Diagnostics Using Production Data and Flowing Pressures
Authors: Anderson David , Mattar Louis 
Published: December 2007

Abstract
There have been tremendous advances in the science of production data analysis in recent years. Three of the most important examples are the inclusion of flowing pressures into analysis methods, the usage of a "boundary dominated" equivalent production time function to make constant rate and constant pressure equivalent, and the use of pseudo-time, which corrects for varying gas properties with pressure. In theory, these advancements enable more sophisticated analyses, accompanied by more reliable results. However, it must be realized that their value is strongly dependent upon the quality of "real" production data, and more importantly, the analyst's ability to filter out the "junk" and retain the true reservoir signal. The blind application of modern decline analysis methods, without consideration of data quality issues, can lead to misinterpretation and erroneous results.
This paper presents several practical diagnostic procedures, some general and others specific, that can be applied to production data, both on simple production charts and on advanced typecurves. Some examples include identifying liquid loading and changing wellbore skin, detecting a shift in well productivity, and diagnosing external pressure support and interference. Field examples are presented to illustrate the effectiveness of these diagnostics. This paper represents the first and only compilation of practical diagnostics for advanced production data analysis that the authors are aware of. The potential benefit of this work is that it will enable engineers at the operational level to more effectively apply advanced analysis techniques to real data, by limiting the possibility of misinterpreting the data.
Some Pitfalls in Well Forecasting
Authors: Williamson H S , Sawaryn S J , Morrison J W 
Published: December 2007

Abstract
Monte Carlo simulation is rapidly superceding deterministic methods as the preferred technique for many well forecasting applications. This paper contrasts the two techniques and highlights the potential benefits of the former. The main part of the paper is a discussion of the application of Monte Carlo simulation to time and cost estimation of single wells, and in particular of some common errors which the authors have observed practitioners to make (or have themselves made) in this context. This discussion, together with sections covering multi-well programs, scheduling, and production issues, demonstrate that although Monte Carlo simulation has the potential to enhance the reliability of well forecasts, this potential can be realized only if the technique is applied with great care.
Best Practices from RPM-Fracturing Treatments in Colombia, South America
Authors: Pinto Sandra González , Izquierdo Guillermo , Téllez Oscar 
Published: December 2007

Abstract
Approximately 30 relative permeability modifier (RPM) fracturing treatments performed in Colombia will help establish consistent, reliable best practices for future applications. Some of these treatments combined scaling inhibition stages to maintain production enhancement, in spite of high or medium formation water scaling tendencies. Because the water-injection system is significantly dynamic in these fields, new injection water channels were communicated with producer wells after RPM-fracturing treatments, reducing scaling inhibition requirements and RPM effectiveness for water production management.
The objective of combining RPM and fracturing treatments was to increase oil production over time through effective water production control techniques.
Evaluations of the effectiveness of both general and specific treatment processes and service are available in the industry. However, data for the analysis of RPM-fracturing treatments presented in this paper was obtained in two basic procedures:
The workover operating efficiency (WOE) index was established to evaluate fracturing effectiveness (total fluid production increase) and RPM effectiveness (water-oil ratio [WOR] reduction). The WOE index quickly analyzes all treatments and identifies the best-performing ones based on two factors: (1) production-related WOE indexes higher than one, which is the maximum production rate after treatment vs. the minimum production rate before treatment, and (2) WOR-related indexes lower than one, or the minimum WOR after treatment vs. the maximum WOR before treatment. This analysis can quickly define the best and worst performances by evaluating individual fracturing effectiveness and individual RPM effectiveness. The reservoir-performance analysis is a cyclical and detailed process that does not focus on individual wells but rather analyzes the entire reservoir. This stage consists of an extensive analysis that involves reservoir characterization, well testing and production history, completion design, stimulation operation design, and stimulation operation execution and feedback.
Because this analysis was so extensive, it was applied only to the best- and worst-case scenarios (two different fields) in which combined RPM-fracturing/scaling inhibition treatments had been in effect for more than 2 years. Those two fields presented some similarities in terms of producing-zone depth, reservoir character, reservoir fluid properties, and water-injection systems.
Both general and specific processes for treating and servicing wells have been evaluated for effectiveness by the industry. Applying the results of the two analyses presented in this paper, best practices are now defined for future well selection, treatment design, and operation execution for combined RPM-fracturing/scaling inhibition treatments.
After-Closure Analysis to Identify Naturally Fractured Reservoirs
Authors: Chipperfield Simon 
Published: December 2007

Abstract
After-Closure Analysis (ACA) in homogeneous matrix reservoirs provides a method for extracting critical reservoir information from pre-frac injection tests. This paper extends the theory and practise of ACA to identify the presence of productive natural fractures.
Natural fractures are important to identify prior to conducting a stimulation treatment because their presence may require designs that differ from conventional matrix treatments. Literature shows that naturally fractured reservoirs are very susceptible to formation damage and require stimulation treatments to account for this issue. The historical problem however, has been to confidently characterize the reservoirs pre-frac, both in terms of the reservoir quality and deliverability mechanism (fractures versus matrix), prior to committing to these design specifications.
This paper presents the results of a simulator used to analyse the mini-frac after-closure period to identify the presence of natural fractures. The simulation results are distilled to a field implementation methodology for determining the extent of natural fracturing and the formation reservoir quality. Unlike previous mini-frac analysis methods, this approach identifies natural fractures that are material to production and allows the engineer to distinguish them from ‘fissures’ that are open only during injection and are not a production mechanism.
Optimization of Injection Field Design with Consideration of Cost and Pressure Constraints Under Conditions of Uncertainty
Authors: Fontaine Russell C. , Anderson Jeffrey A. , Hunter W. Alan , Tubbs Dallas H. 
Published: December 2007

Abstract
A unique approach has been developed to optimize injection for managing excess produced water at oil and gas fields. A simulation case study is presented demonstrating how the approach helped ChevronTexaco to quantify ultimate injection volume, number of injectors, injection rate per well, and well location for two sandstone aquifers downgradient and fault separated from their associated oil reservoirs. The approach combines stochastic, deterministic, and optimization models and is flexible to honor all the available data and also incorporate uncertainty in the field parameters (e.g. permeability distributions, boundary and initial conditions, and geologic barriers). A stochastic version of the model is best used to assess uncertainty in the geologic and pressure regimes. These runs are preceded by traditional deterministic simulation techniques, including history matching to the available pressure transient data. Once the scenarios have been selected, optimization simulations quantify the optimum number of injection wells and location, and the total volume of water that can be injected over the period of interest. A particle tracking technique is also used to define the pathways of the injected water and assess its ultimate fate and potential impacts. This approach can be used cost effectively to optimize produced water management under conditions of uncertainty with a sparse data set.
Central Waste Treatment Facilities (CTRD) Reduce Drilling and Waste Management Costs in Heavy Oil Operations, Eastern Venezuela
Authors: Arrocha Alfonso , Ellis Gustavo , Browning Keith , Redfern Kevin , Bernal Gonzalo 
Published: December 2007

Abstract
The Ameriven Central Waste Treatment Facilities (CTRD Centro de Tratamiento y Recuperación de Desechos), which were designed and implemented with the technical support of teams provided by a major drilling waste management service company, receives and processes heavy-oil drilling and production waste generated by operations in the Hamaca Project, located in the Faja Region of the Orinoco Belt in Venezuela.
The CTRD operational strategy emphasizes the 4Rs: reduction, reuse, recovery, and recycling. Important cost savings have been achieved from: (1) the consolidation of waste treatment at one location near the source; and (2) the efficient waste management practices implemented by the fluids and waste management team, under contract with Petrolera Ameriven (Ameriven). The facility now serves as a model for similar operations in the region and has earned unconditional approval from governmental agencies and prominent companies with commercial interests in the area's forests and resources.
Over the life of the 30-year project, the facility will process the waste from approximately 250 to 500 wells. The current development production phase yields 80,000 bbl/day, with 190,000 bbl/day extra-heavy crude expected in the commercial production phase. Cost reductions related to waste management and disposal at this site are currently estimated at 22% (since commencement of operations) and are expected to improve further as the facility is used to full capacity.
Several integrated processes are implemented for the efficient disposal of drilling waste products: thorough rig audits, solids-control equipment performance, rig, field, and plant supervision, dewatering, water treatment, and landfarming and landspreading of processed solids and cuttings.
High-Speed Pressure and Accelerometer Measurements Characterize Dynamic Behavior During Perforating Events in Deepwater Gulf of Mexico
Authors: Schatz J. F. , Schatz John F. , Folse Kent C. , Fripp Michael , Dupont Richard 
Published: December 2007

Abstract
With the current oilfield trend to pursue prolific oil and gas producers in the deepwater markets around the world; operators are drilling and completing larger boreholes to deliver and accelerate the production stream more effectively. Typically, in deepwater environments, the intervals to be perforated tend to be longer than on shelf-type completions. In addition, deepwater completions are more complicated with stacked pay zones that require additional completion steps and associated hardware. To execute these larger completions, operators normally opt to choose the largest perforating assembly that will yield the best charge performance (casing-entrance hole diameter and formation penetration) at in-situ conditions. These larger perforating systems with higher shot densities and total explosive load have the potential to create very large fluid-pressure waves and solid shock loads that can cause damage to the completion (unset packers, move bridge plugs, buckle tubing, split casing, etc.) under certain conditions.
Because of the added expense of completing wells in the deepwater arena, problems during the perforation process can considerably increase completion expenditure. To help minimize potential risk during the completion program, it is critical to understand the dynamic pressure and shock events that occur during perforating.
This paper will present a new numerical model that helps to ensure service quality by improving reliability on deepwater completions. The model has been validated with field measurements and employs high-speed recorders that were previously dedicated primarily to validating burn parameters for propellant-type equipment.
Combining SBM Modeling and Drilling Data to Elucidate GOM Well Problems
Authors: Iyoho A. W. , Kunning J. R. , Oskarsen R. T. 
Published: December 2007

Abstract
This paper discusses a field-applicable wellbore hydraulics simulator for modeling cement displacement using SBM (synthetic-based mud) inside casing strings, and calculating ECD (equivalent circulating density) and SPP (standpipe pressure) while drilling with compressible mud. The paper shows how drilling data and model results can be used collaboratively to improve the understanding and solution of well problems. The spreadsheet-based simulator consists of readily available models designed to describe the behavior of SBM under typical conditions encountered in deepwater GOM (Gulf of Mexico) operations. The algorithms account for water depth, pressure, temperature, mud composition, viscosity, wellbore size, and cuttings loading throughout the wellbore.
Field tests in straight holes where PWD (pressure-while-drilling) tools were run show good results. Typical errors between calculated and measured ECD were In the casing cementing study, measured cement displacement volume to bump the plug compared favorably with model predictions, after proper considerations of compressibility. Applications to high-angle wells require some adjustments.
Perforation Morphology and the Onset of Sand Production
Authors: Walton Ian C. , Chang Frank F. , de Cardenas Jorge Lopez 
Published: December 2007

Abstract
In cased-hole completions the perforations constitute the essential link between the wellbore and the reservoir. Weak formations are often prone to sand production during or immediately after perforating. The industry has developed a range of techniques to either control or prevent sand production, including sand screens, gravel packs, frac-packs and screenless completions, and oriented. Selection of the appropriate technique depends on rock properties, in situ stresses and an estimate of cost and risk of sand production and potential remedial interventions. To make better-informed decisions one must understand the mechanism by which sand is produced into the wellbore and this in turn is dependent on the morphology of the perforation tunnel created in the formation.
This paper reports on experiments undertaken in Schlumberger's perforating laboratory in which shaped charges are fired into rock samples under stress conditions typical of those down hole. Using rocks of various different strengths we are able to categorize the perforation tunnel morphology as competent, rehealed (closed), failed or collapsed depending on the in situ conditions and the perforating designs. This morphology is a primary determinant of the risk of sand production and is the starting point for developing mechanistic models of the sand production process.
Transport of failed rock fragments into the wellbore is dependent on the flow rate of reservoir fluids through the perforation. In the laboratory experiments the pressure in the wellbore adjacent to the perforations is measured with a highspeed pressure gauge, from which the surge flow rate is calculated. We have discovered that surge flow rates are most intense during the first second after detonation of the shaped charge and it is therefore at this time that the formation is prone to sand failure.
In the paper we present details of the experimental program including analysis of the perforation morphology and the wellbore pressure profiles during perforating.
Deepwater Core Comparison with Answers from a Real-Time Petrophysical Evaluation
Authors: Poulin M. , Hidore J. , Sutiyono S. , Herron M. , Herron S. , Seleznev N. , Grau J. , Horkowitz J. , Chabernaud T. 
Published: December 2007

Abstract
Rapid petrophysical evaluation is critical in such expensive venues as the deepwater Gulf of Mexico. Recently, a real-time petrophysical analysis program was introduced based on the combination of elemental concentrations from spectroscopy and standard triple-combo logging1. The application consists of a spectroscopy-based quantitative lithology consisting of total clay, sand, carbonate and pyrite2. Elemental concentrations are used to correct neutron and density for matrix effects3 to directly compute total porosity and to correct for lithology and thereby enhance neutron-density crossover in the case of gas. Intrinsic permeability is computed from the lithology and total porosity using the k-Lambda approach4. Water salinity is input and water saturation is computed using the Waxman-Smits-Thomas equations and porosity and lithology5,6. Finally, irreducible water saturation is computed from the Coates-Timur7,8 equation using the calculated porosity and permeability.
This rapid, automatic petrophysical interpretation has been applied to data from a cored well in the deepwater and comparison with core data demonstrates the validity of the porosity, permeability, and saturation evaluations. Computed total porosity is in very good agreement with core values. Computed permeability is generally within a factor of three of measured permeabilities. Computed water saturation is also in good agreement with core values, partially due to the use of oil-based mud.
However, in spite of the accurate petrophysical evaluation, the interpretation was initially suspect due to a significant discrepancy between the computed clay content and the core values measured by x-ray diffraction (XRD). XRD clay averages less than half of the values computed from spectroscopy using the default subarkose model. In order to investigate this discpreancy, twenty plugs were analyzed for major and minor element chemistry and for mineralogy by dual-range Fourier Transform Infrared (DRFT-IR). DRFT-IR mineralogy is independently validated by comparison with chemistry and is in good agreement with wireline computed total clay. Finally, these DRFT-IR and chemistry data are used to produce an optimized total clay from chemistry model that can be used in existing or future wells in this field with spectroscopy data.
Decision Granularity: Preserving Uncertainty Information in Data Consolidations
Authors: Allan Paul D. 
Published: December 2007

Abstract
While risk analysis and stochastic considerations are widely applied in the analysis of individual projects or wells, frequently this information is lost or misrepresented when data is rolled-up at a division or corporate level. Strategic plans or capital allocations based on the consolidation of expected value descriptions mask the range of uncertainty and performance probabilities inherent in these decisions.
The techniques and mathematics involved in stochastic aggregation are relatively well known, yet not widely applied in corporate planning organizations due to time constraints, data availability, available tools, or data management issues. In many cases, planning organizations rely on historical averages or consolidations of specific scenarios to gain insight into their business uncertainty. These may provide useful insights into the business, but can oftentimes be misleading. Changes to the portfolio over time may make historical assumptions invalid and an aggregation of a specific scenario may represent a possible but highly improbable outcome.
This paper describes a simple method for stochastically aggregating projects, preserving uncertainty information as data is rolled up to a division or corporate level. Case study data and computer modeling will be used to demonstrate the benefits of accurately reflecting stochastic data in aggregations and the problems associated with relying solely on expected value descriptions. The techniques and methods described in this work provide a means for better matching decision granularity (the level at which decisions are made) and the underlying data (the level of data consolidation).