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The performance of the centrifugal pump used in Electrical Submersible Pumps (EPS) is significantly degraded by the presence of gas in the fluid. This greatly reduces the applicability of the pump. Rotary separators, separating devices that used the pump shaft rotation to force the gas from the liquid were developed over twenty five years ago. In situations where even the rotary separator could not remove enough gas form the fluid, tandem or stacked rotary separators were often used.Improved models of rotary gas separators have been developed and introduced.

This paper reports on the testing and development of a new generation of gas separation technology for Electrical Submersible Pumps. Active (rotary) gas separators were introduced to the market 20-25 years ago, and no major improvements have been made since Accurate testing of gas separators has always been fraught with problems, sometimes producing confusing and misleading information. An in-depth study and testing of the separators in a high pressure gas testing loop has indicated some methods to improve the gas separator performance.

Horizontal completions in lower permeability formations often result in a need for effective hydraulic fracturing stimulations for many of these wells to reach economic production levels. Cost constraints seldom allow the use of methods such as cemented completions and individual fracturing of numerous zones with bridge plug isolation. Some newer methods require expensive downhole jewelry.

Through the years, oil operators have discussed the pros and cons of holding tubing backpressure in rod pumped wells. Although backpressure on tubing is not a panacea for every well, there are definitely applications where it can aid in the operation of a rod pumped system. Most commonly, backpressure is used to prevent a well from "flowing off" at surface when gas is present in tubing fluid column. Backpressure may also be used to increase differential pressure across pump valves when needed.

This paper describes how baked-on coatings are being employed as economical corrosion and paraffin control devices in the Permian Basin Area. To illustrate and explain the influence of "Quality Assurance" upon the economics which support having tubular goods coated, a string of tubing is followed through a baked-on coating process. It is concluded that the economics favoring baked-on coatings are no stronger than is the coating process.

Baker Hughes Drill Bits recently launch the new Talon Bit which was derived from years of engineering experience and reiterations of bit designs. Baker Hughes Drill Bit Engineers have tested many different frame styles that have lead to the optimized drilling and efficiency of the Talon Bit. The Talon Bit has continuously enabled operators to increase their rate of penetration, reach target depths with one bit which leads to cost savings.

Banks have been making loans secured by oil and gas production since the 1920"s. The nature of oil reservoirs was not understood very well at that time, and the early oil bankers were handicapped by a lack of reliable oil- and gas-reserve reports. The problem was compounded by wildly fluctuating oil prices. The development of instruments for obtaining bottomhole pressure and temperature, cores, and reservoir fluid samples and the development of the ancillary laboratory equipment for measuring the core and reservoir fluid properties paved the way for the development of reservoir engineering.

Many engineers, when faced with the necessity of designing a fracture treatment for a well, will either look to the experience of other operators in the field or will rely on a service company for the design. Although these courses of action have merit, they do not always result in the most effective treatment for a particular situation. It is essential therefore, that the engineer have a knowledge of basic design methods and an understanding of fundamental fracturing concepts if he is to intelligently recommend a fracture treatment for a well.

Over the last decade the use of the pressure derivative as a diagnostic tool in pressure transient analysis has grown immensely. The modern well test analyst turns to the derivative log-log plot almost exclusively to formulate a first opinion on well test behavior. The pressure derivative essentially allows the analyst a magnified view of the distinctive pressure behavior associated with various wellbore and reservoir phenomena.

A typical submergible electric pumping unit is composed of seven basic components: electric motor, multi-stage centrifugal pump, protector, power cable, motor flat cable, switchboard and an auto transformer, single three phase or a bank of three single phase transformers. All of the above equipment is manufactured in numerous sizes and types to fit the well specifications, such as casing size, desired producing volume, total lift, electrical power supply and environment. In addition to these basic components, various auxiliary items are used. Some are required, while others are optional.

It is becoming increasingly important for technical personnel in the petroleum industry to have a background in filtration and separation techniques. One of the principal reasons for this need is demonstrated by the number of enhanced oil recovery (EOR) projects currently in operation. Anytime contaminated fluids are introduced into a subsurface formation there is a risk of damage. In the case of water and gas flooding operations where large volumes of fluid are injected, levels of contamination become acute problems.

Packers are run in oil and gas wells primarily to confine fluids. Usually the objective is to confine high-pressure or corrosive fluids and/or, in the case of multiple completions, to confine the fluid to specific tubing strings. Many side benefits are obtained because of the confinement; such as, protection of the casing from high-pressure or corrosive fluids, separation of zones in the well bore, directing the flow of treating fluid, and also as a safety feature.

Mainly due to its long history, sucker rod pumping is a very popular means of artificial lift. Nearly two thirds of the worlds producing oil wells are on this lift. This paper reviews concerns that producers are faced with today when using inadequately designed sucker rod pumping designs, and suggest basic methods to assist with those concerns. In general, sucker rod pumping applications can be very effective when properly designed.

Where shall we drill? Is there oil in this zone? What is the best place to perforate? Where can we find water for this flood? From where is this water coming? How much oil is there in this zone? Where is the best place to inject? Did we pass up some good reserves? Why is the gas to oil ratio increasing? The answers to these common questions result in decisions which both cost and make money. Proper use of electric logs can help solve these problems many times. For this reason production personnel should be familiar with the principles of log interpretation.

The energy provided by salt water in an oil reservoir is one of the best known oil recovery mechanisms. Salt water should be considered a tremendous asset to oil production, rather than a liability, and it should be intelligently handled. Progressive companies recognize the value of salt water, as well as its dangers. Provision for its handling is made in the budget along with other development and operating costs. The most satisfactory method of disposing of large volumes of salt water in inland areas is by subsurface well disposal.

The handling, installation, and after-operations are all very important factors to ensure successful submergible pumping operations. This paper recommends the basic practices to follow for each of these subjects. It is felt that if these practices are followed, it will result in successful submergible operations for the user. The bottom line is that the producing company must be the major contributor who enforces good working practices that are pertinent to their operations and result in economical results.

Packers used in oil wells date back to the earliest oil fields. The first packers were homemade and were generally a wooden plug-rag packer made by wrapping rags around a pipe, or steel wool or lead packed in the bottom of the hole with tools. Most of this early work was in open hole. Modern completions where casing is set through, cemented, perforated and acidized increased packer usage, giving rise to packer service firms that furnish tools and service to perform a treating job on a rental basis. These service tools are patented and are not sold.

The results of a pilot inhibition program carried out on eight wells on the MCA Unit, Maljamar, New Mexico, form the basis for a batch treatment program that has been translated to over 400 producing wells in the Hobbs area. The recommended treatment program will be discussed with respect to selection of inhibitor, batch treatment methodology, frequency of treatment, and inhibitor dosage. Results showing the effectiveness of this program with regard to corrosion mitigation, increased production, and improvement of the quality of the produced oil and water will be presented.

The Beam Gas Compressor

A number of different methods of controlling beam pumping units are in use today and the important features of each are considered. Most of these controllers use the polish rod load (measured directly or by inference from the motor load) to determine the performance of the rods and pump downhole in the well. Whenever a variation in the rod load is seen indicating that the pump is not full of liquid, the controller shuts down the pump - usually for a fixed period of time.

New results have appeared for downhole pump slippage predictions from fairly recent test data. Additional testing is in progress. A pump with large plunger/barrel clearances will slip more fluid. A pump with smaller clearances will slip or leak less but a tighter fit will tend to increase rod buckling at the pump to a greater degree. Considerations for pump leakage and example calculations are presented using the older and the new pump slippage relationships. Also the effect of pump clearances on possible buckling are studied.

Training techniques used in Continental Oil Company's Well Pumping Short Courses will be discussed. The API recommended practice (RP 11L) for calculation well loads, peak torque, polished rod horsepower, etc., will be presented in "building block" form. An understanding of instantaneous net torque calculations using torque factors will be secured. Typical rod pumping problem areas and possible solutions by utilizing standing valve and traveling valve tests vs.

With the advent of Shale gas, fractured horizontal gas wells are the preferred method of well construction. Figure 1 illustrates production from Shale Gas. The well construction of horizontal wells can take on many forms. Figure 2 shows that horizontal wells can be drilled up from the kick off point, approximately horizontally from the kick off point and downward from the kick off point. The wells can be more complex than shown in Figure 2 and of different depths than illustrated.

Variable speed drives have changed the way beam pumping units keep wells pumped down, prevent failures, and extend the life of the machine. VSDs, although slow to be accepted are now a typical portion of the control mechanism found in pumping units. In this paper, we will review the history of VSDs in the oilfield, provide an overview of where they are now an take a glimpse into the near future of developments.

The phenomenon of sulfide stress cracking (SSC) can result in catastrophic failures of pressurized equipment and piping, resulting in extensive damage, injuries and possible fatalities. Sulfide stress cracking was first identified as a serious problem in the oil industry in the late 1950's with the development of deeper sour reservoirs. The high strength materials required for these wells began to fail as a result of brittle fracture that was later identified as SSC. Research began on this phenomenon, and a task group was formed, which later became associated with NACE.