Corrosion inhibitors developed for low alloy metals have been found to have limited use on stainless steels such as 13Cr. Stainless steels are being successfully used to combat H2S and CO2 corrosion but are proving susceptible to hydrochloric acid (HCl). This paper presents results of tests made with 13Cr steel subjected to corrosion by HCl. Several inhibitors and inhibitor systems are compared under varying temperatures and acid concentrations. These comparisons reveal (1) 13Cr steel's greater susceptibility to corrosion than that of low alloy N-80 steel, and (2) the effects of different corrosion inhibitors in reducing the attack on the metal tested.

Successful corrosion control in producing oil wells depends upon two indispensable factors: 1. The inhibitor
must be capable of controlling the corrosion, and 2. The inhibitor must be applied on a rigid schedule
and in a manner which will insure that it comes into contact with all surfaces to be protected.

Corrosion monitoring is the foundation of a corrosion control program. The information derived is necessary to determine need, extent, and performance of corrosion control measures. This paper discusses corrosion monitoring in oil and gas production. Basic philosophy is presented. Many different types of monitoring methods are addressed. The advantages, disadvantages, and application of each are presented. Emphasis is placed on methods addressing corrosion by produced fluids. Only common field methods are discussed. Techniques for monitoring cathodic protection systems are not covered.

Knowledge of the various approaches to solving corrosion problems and familiarity with corrosion control techniques are important to the "profit improvement programs" of today's oil and gas producer. This paper presents a resume of internal corrosion problems and corrosion control methods in the producing industry. The basic causes of corrosion and basic methods of control are reviewed. The effects of the many oil patch environments on production equipment will be mentioned. The options for corrosion control will be discussed for several general problems including: down-hole corrosion in various types of producing wells, separation equipment and tankage corrosion, and water system (waterflood and disposal) corrosion. The paper attempts to help the reader "scope in" on his specific problems through an awareness of the over-all picture. A list of "Additional Reading" will be included for those who want to dig deeper into specific subjects. The verbal presentation will be illustrated by approximately 100 35mm slides.

Operators have used equipment and parts made of stainless steels in Permian Basin oilfield operations for years. The material is an improvement over carbon steels in corrosive water environments, but stainless steels are a poor choice when used in sour high chloride produced water service. Parts made from stainless steel in this service are subject to chlorides-induced corrosion. The problem can be even worse when the part is also subjected to fatigue loading.

Most corrosion problems in packer fluids occur from small concentrations of materials unintentionally added to the packer fluid or from foreign materials that contaminate the fluid during or after its placement. Bacterial growth, as well as oxygen saturation, can be responsible for corrosion in mus systems. Oxygen and sour gas contamination are the most common corrosive agents in brines, while oil gives the most trouble-free system from a corrosion standpoint. Consideration of a few corrosion fundamentals will permit the engineer to make the choice of a chemical treatment for a given packer fluid or choose a packer fluid which will give the most protection to casing and tubing. Special fluids and related dead space corrosion problems are briefly considered.

This article is to present how the convergence of wireless technology with internet data presentation provides the savvy producer capabilities and solutions to operate more efficiently, optimize production and create greater efficiencies throughout the organization. It will present issues of wireless data techniques and the capabilities remote monitoring is presenting to the market place. It will touch on how these tools can be used in investor relations and can be applied to mezzanine financing situations in order to secure financing in some situations.

This paper focuses on approaches to eliminate problems occurring in the production system instead of treating each of the symptoms. Evaluations start with downhole treatment and its effect on eliminating or creating problems at the battery. Problems at the battery are next considered since they contribute to problems at the injection well. The impact of proper downhole corrosion treatment on water and oil quality, corrosion, the load to surface treating equipment will be considered. Adverse effects of using too much chemical as well as multiple chemicals will be illustrated. An oxygen exclusion principle is presented. Ultimately cost benefits arising from lower oil in water carryover, less filterable solids, fewer workovers of injection wells, will be highlighted with examples from the field.

Historically, multi well platform directional drilling has been challenging especially in the initial drilling phase. Wells have to be carefully navigated through a maze of other wells and eventually steered clear of all interfering wells to the desired target. (ref #1) To avoid drilling into another well, ellipses of uncertainty and well proximities are calculated as part of the well planning program so that each well can be monitored relative to the others wells around it and collisions avoided. (Ref # 2) As well as an appropriate well plan, the survey tools used for the drilling phase must be modeled and any errors taken into account when the drilling phase is underway. All navigation orientation systems used on modem multi well structures will be either gyroscopic for the top hole, or magnetic systems, once the interference section of the hole has been overcome. Because of the proximity of other wells it is impossible to use any magnetic based survey system in the initial part of the well so gyro survey tools are normally used to give the directional driller the required azimuth and toolface data he requires to orient and steer the motor assembly through this hole section. A typical bottom hole assembly for this initial top hole phase consists of a bit, motor, bent sub or a bent housing motor, orienting sub, non magnetic drill collar, heavyweight drillpipe and drill collars. The orientation of the bent sub and motor is facilitated by the alignment of a key in the orienting sub with the highside scribeline of the bent sub (Ref # 3). The bottom of the gyro tool is dressed with a muleshoe which will locate the key in the sub and force the gyro tool to seat with the muleshoe properly aligned in the keyway. (Ref # 4). This means that any toolface reading from the gyro will indicate the direction in which the motorbent sub is "pointing". By placing weight to this assembly, the bent sub becomes the fulcrum and the bit is forced to the highside of the hole thereby initiating a building of hole angle. The severity of the bent sub angle will determine the rate of build.

Since the early days of artificial lift of oil, much has been said and written about the importance of proper counterbalance of the loads involved. Unfortunately, little has been done in the industry toward the systematic checking of pumping units to insure that the best counterbalance possible is being maintained. As a result, the industry loses heavily every year, this loss being in energy expended uselessly and in equipment damaged by overloading. Counterbalancing may be defined as the effort to offset the rod load on the gear box and the prime mover. Several different systems are used, and the method is not particularly important. For beam-type pumping units, the present most generally accepted methods of counterbalance are using beam weights, crank-type weights, and compressed air.

Capital and power consumption costs for sucker-rod pumps depend, in part, on the counterweight torque. Counterweight torque is the primary variable because peak torque depends on how well the well is balanced. The secondary variables affect the ideal counterweight torque (motor slip, pumpjack efficiency, net lift, and torque equation). High slip motors allow more crank speed variation. Pumpjack efficiency (preventive maintenance) affects power consumption. Net lift changes the net crankshaft torque as the well pumps off. The general form of the net torque equation more accurately converts polished rod forces into equivalent moments at the crankshaft than the simplified counterbalance equivalent equation. Each combination of the primary and secondary variables may have a unique counterweight torque that minimizes the peak net crankshaft torque by equalizing the largest upstroke and downstroke torques. The peak torque affects capital costs for the assumed operating and preventive maintenance conditions by determining the smallest acceptable gearbox and motor sizes. Fully loaded motors use less electricity because power factor and electrical efficiency go up with the ratio of brake horsepower to motor horsepower. In short, it is possible to cut capital and power consumption expenses by managing the difference between the ideal and the actual counterweight torques throughout the life of the well. Pumpjacks are counterbalanced for an ideal operating condition that considers motor slip, mechanical efficiency, and a fluid level that falls to the pump. The latter element indicates that normally operating pumpjacks have multiple ideal counterweight torques. Careful torque predictions for the anticipated range of operating conditions can save capital by reducing gearbox and motor requirements. Specifying the smallest acceptable motor reduces power consumption because the power factor increases when the nameplate rating is close to the brake horsepower. Brake horsepower is affected by mechanical efficiency and counterweight torque. High mechanical efficiency comes with maintenance. A preventive maintenance goal is to reduce total operating cost by lowering power consumption. Thus power consumption and maintenance costs are an economic tradeoff for the life of the well. Counterweight torque also affects power consumption because it takes a bigger motor to handle the higher peak torques caused by improper counterweight torque. A well-balanced pumpjack uses less power because the ratio of brake to motor horsepower is higher when the crank is ideally counterweighted. Calculated counterweight torque accuracy depends on the selected equation. The net crankshaft torque equations are more SOUTHWESTERN PETROLEUM SHORT COURSE

Capital and power consumption costs for sucker-rod pumps depend, in part, on the counterweight torque. Counterweight torque is the primary variable because peak torque depends on how well the well is balanced. The secondary variables affect the ideal counterweight torque (motor slip, pumpjack efficiency, net lift, and torque equation). High slip motors allow more crank speed variation. Pumpjack efficiency (preventive maintenance) affects power consumption. Net lift changes the net crankshaft torque as the well pumps off. The general form of the net torque equation more accurately converts polished rod forces into equivalent moments at the crankshaft than the simplified counterbalance equivalent equation. Each combination of the primary and secondary variables may have a unique counterweight torque that minimizes the peak net crankshaft torque by equalizing the largest upstroke and downstroke torques. The peak torque affects capital costs for the assumed operating and preventive maintenance conditions by determining the smallest acceptable gearbox and motor sizes. Fully loaded motors use less electricity because power factor and electrical efficiency go up with the ratio of brake horsepower to motor horsepower. In short, it is possible to cut capital and power consumption expenses by managing the difference between the ideal and the actual counterweight torques throughout the life of the well.

Drilling and completing long, horizontal sections in low to moderate permeability reservoirs has become commonplace in many oil and gas producing regions of the world. Economically successful exploitation of these types of reservoirs usually requires hydraulic fracture stimulation in both vertical and horizontal completions. Many completion techniques have been used for fracture stimulation of horizontal wells. Multiple stage fracturing treatments are highly effective, but the high cost and risk associated with this type of completion often make it unattractive. Limited-entry fracturing has proved to be an effective stimulation method for horizontal wells with an acceptable level of cost and risk.Successful limited-entry fracturing of horizontal wells is highly dependent on effective zonal isolation and perforation design. This paper presents a case history of horizontal completions using limited-entry fracture stimulation. Zonal isolation methods, perforating strategies, and their effects on limited-entry fracturing success are discussed and compared.

As the price of energy and services increase, even greater attention will be focused on all aspects of scale deposition. The detrimental impact of scale deposition continues to compel the industry to develop new technologies and innovations in scale control and prevention. One area where this has been especially challenging is in hydraulic fracturing treatments. As well completions and fracturing treatments increase in cost, size, and complexity, the demand for cost effective scale control has increased accordingly. Potential scale deposition problems need to be evaluated and strategies for prevention and control need to be planned before the well is completed and stimulated. Previous papers have addressed new products, technologies, and applications, but few have provided a process for scale inhibitor design in hydraulic fracturing treatments. This paper will attempt to provide criteria for planning and design of these scale inhibitor applications by addressing inhibitor selection, placement, loading, and experience.

A properly designed sucker-rod string should provide failure-free pumping operations for an extended period. According to its prime importance in sucker-rod pumping technology several design procedures based on different assumptions were developed in the past. Correct description of rod loading conditions during the pumping cycle led to the inclusion of fatigue endurance limits into rod string designs and discusses their main characteristics; design results are compared for example cases. The paper also provides a more thorough comparison of designs involving the calculation of loads and stressed predicted from the solution of the damped wave equation. Using a predictive analysis program rod stresses are calculated that, plotted on the modified Goodman diagram, provide a proper comparison of merits of the different rod string design methods.

Separator design and sizing is often done without full appreciation or understanding of the problem of foam. Many field and lab tests using probes and windows have shown that foam is often the major problem for the typical crude oil degassing, flash, separator. Often more than 50% of a separator's volume is occupied by foam. All crude oils should be considered foamy because any oil can create large foam volumes under certain conditions. The size of the separator foam volume depends on many interrelated factors. There is no single magic key to determining foam volume. Derating of the allowable gas velocity to account for foam is a grossly inaccurate method of separator sizing. The K-factor in the allowable gas velocity equation correlates to none of the factors that affect foam volume. Fritted bubbler and pressure bomb indexers are a step in the right direction but are still inadequate. We have developed a pilot operation which with proper foam generation can produce meaningful oil foaminess measurements. To predict separator foam volumes, several adjusting factors must be applied. The heart of an accurate foam volume prediction is an abundance of field experience correlated with laboratory pilot data, which includes all pertinent variables.

Hydrogen sulfide gas is present in much of the crude oil and natural gas production throughout the world. This creates quite a problem for today's producers, in that the hydrogen sulfide is both poisonous and very corrosive. In the past, the need to reduce hydrogen sulfide (Has) by "sweetening" was born more of necessity than environmental good intentions. The high toxicity of H2S simply made it imperative. It is only in recent years that scientists have discovered that these gases also contribute to acid rain and the destruction of our irreplaceable ozone layer. Now, with the addition of these serious environmental implications, the issue of sweetening produced oil, gas, and water containing H2S has taken on an even greater importance. Unfortunately, addressing this environmental responsibility is further complicated by old gas sweetening techniques that have traditionally forced you to accept certain compromises in efficiency, cost of production, and even the quality of your end product. Many of these methods of H2S removal involve the use of heavy metals and known carcinogens that result in a waste product which is hazardous to man and the environment, as well as having the requirement of being disposed of at an EPA approved disposal site. In addition, these methods are known to be non-selective in their removal of H2S, also combining with large quantities of carbon dioxide, compromising the quality of your finished product. Essentially, wasting product by removing carbon dioxide from your production rather than simply getting the H2S out.

Cryogenic freeze techniques can be used for temporary pressure isolation of wellheads, casings, pipelines and other tubulars in land and off-shore applications, but current practice requires zero flow for use of these methods. Biofilm IP LLC (Biofilm) has created a patent pending thermodynamic valve methodology and apparatus and has demonstrated pressure isolation of flowing crude oil.

The Midway FMT is a Spraberry waterflood located in Dawson County about 10 miles southeast of Lamesa, Texas that has a history of paraffin problems. The severity of problems range from having to abandon flowlines that plugged with paraffin, to back pressure on flowlines, to reduced production rates, to having to hot oil or hot water flowlines, to injecting paraffin solvents and paraffin inhibitors and / or combinations of the above. Paraffin build-ups in tubing can result in decreased flow rates, expense and delayed production due to field or contract wireline cutting and steaming the tubing. The goal of the Midway FMT is to maximize production while investigating ways to reduce controllable expenses through chemicals and associated costs. This paper describes a method to help control paraffin using a chemical program developed by Unichem called the Crystal Modifier Project. The objective of this program is to reduce failures and costs associated with paraffin.

This paper compares several different types of production prime movers, their operating costs, and how to cut costs. Examples are given of actual operations in Texas oil production.

Formation evaluation is the process of the application of technology to gain or improve understanding the physical characteristics of subsurface rock formations and the nature and distribution of their contained fluids for the purpose of identifying and developing commercial hydrocarbons. Cores and rotary sidewall cores are prized as actual samples of subsurface rock formations and their contained fluids and the opportunity they represent for direct measurements and observations of rock and fluid properties. Because of their expense, these assets are not commonly available to formation evaluators. Cuttings, however, are an inescapable by-product of every well drilled. Cuttings provide petrophysical information such as mineralogy, texture and pore system characteristics of all penetrated formations, as well as stratigraphic information through their appearance and content. They also provide fluid samples for relative hydrocarbon saturation estimates and geochemical characterization. This information can be broadly applicable in all phases of the petroleum industry: exploration, reservoir management, and drilling and completion. The process of assuring cuttings circulated to the surface are properly located on depth requires completion of a circulation lag check. The data gathered to calculate lag time can be used further to determine a lag time openhole caliper in near real time, and an average openhole diameter profile of a new wellbore can be developed during ongoing drilling using this information. A new evaluation element based on openhole diameter trends, the cavings factor, is proposed to quantify anticipated cuttings sample quality during drilling. If value is placed on acquisition of valid formation evaluation data in general, and cuttings samples in particular, real time remediation is possible through this focused awareness on the developing geometry of a new wellbore. The skills and the interest in cuttings espoused by subsurface formation evaluators in the early history of the oil and gas industry has atrophied. Today, the proliferation of digital data and mathematical models permits calculation and generation of impressive volumes of formation evaluation output without ever examining those broadly and readily available natural earth samples, cuttings, to validate the results. Should a binocular microscope sit next to every computer on the desk of every technical professional in this industry? As exploration and development proceeds into the next century, formation evaluators should focus on what is central to their profession and strive to use cuttings classically and innovatively. As a sample of subsurface rock material and surface-retained fluids, this inescapable asset can be used to reduce risk and uncertainty in prospecting and development operations and maximize the value of formation evaluation in the oil and gas industry.

To obtain meaningful results from Wave Equation analysis of surface dynamometer data, the acquired field data should meet certain minimum requirements. This paper will show the effects of the various parameters on the Down Hole Cards. Various parameters will be examined and their effects shown. Some of the topics covered will be: The Effects of Sampling frequency, Aliasing, Lowpass Filtering, Data Slew Rate, and Skew between Load and Position on Sampled Data. A technique, improving signal to noise ratio and performance by Over Sampling and Decimation will also be covered. It is hoped that this information will be useful in making informed decisions about system data gathering requirements.

The paper will discuss the fundamentals of the Mark II pumping unit and the torque analysis. Comparisons will be made to other types of pumping units to show where this unit will have a reduced torque and additional operational benefits to the operator.

Most work on the casing plunger has highlighted its concept and technology. This paper will show the true economics of applying this technology. This provides the producer a true, accurate measure to determine his decision on this concept

Unlike traditional oilfield biocides, those created using Electro-Chemical Activation (ECA) technology, do not interference with gel breakers, do not increase TDS levels, leave no residual toxic chemicals, are cost competitive and are extremely effective killing bacteria without the microorganisms becoming resistant to the natural biocide solutions. This paper discusses