A pressure buildup on a pumping well may be conducted by either of two methods. Direct measurement, of course, involves placing a gauge downhole. This presents special problems, however, for a pumping well. Since this procedure involves pulling the rods and pump in order to get the gauge downhole, it is usually economically infeasible. In addition, this "pulling" process introduces a new transient into the formation which adversely affects the analysis unless the well is restabilized once the gauge is downhole. The second method involves acoustically determining the depth to the gas-liquid interface, measuring the casing pressure, and calculating the downhole pressure from these two measurements. With this method, an appropriate correlation must be selected in order to correct the liquid gradient for the gas in the column. The pressure derivative is an analysis tool which has received considerable attention lately. l-6 The two primary applications of the derivative are (1) identifying the different flow regimes and (2) obtaining a unique type curve match. Since the derivative involves a point-wise pressure difference rather than the pressure rise since the start of the test, it tends to amplify even small changes. For this reason, most examples have used data that was obtained from electronic pressure gauges. The purpose of this paper is to show that the pressure derivative may be applied to acoustic data. Two examples will be presented showing (1) a well with wellbore storage and skin and (2) a fractured well.

Since the inception in 1947 of hydraulic fracturing as a method of stimulating oil and gas wells, fractured wells have become a commonplace throughout the world. This is particularly true in regions noted for low permeability and accompanying low productivity. Transient pressure test conducted in fractured reservoirs are subject to unconventional behavior which requires special interpretational skills and procedures. The purpose of this paper is to discuss those methods of pressure analysis which have been most successfully applied to wells that intersect single-plane vertical fractures. Procedures for evaluating reservoir permeability, formation damage, and fracture length are presented for both conventional and type-curve methods of analysis. Practical tests and rules-of-thumb which will help an engineer avoid common pitfalls in fractured well analysis are presented. Both infinite- and finite-conductivity fractures are discussed.

Production logs that are available to the industry today obtain a more accurate account of production; the main reason for the accuracy is that the well is logged in the dynamic production state. Interpretation of the production log is dependent upon understanding the mechanics of the well and the function of the combinations of logs used. The following approach is important in obtaining and interpreting good production logs: 1. Properly prepare the well to be logged prior to survey. 2. Have a basic knowledge of the tools used in each log. Understand the procedure, mechanics, and calculations needed. 3. Understand how to use each log 4. Learn to combine all logs so they present one overall picture of the production pattern. In recent years, the production log has mainly been applied in shallow wells (1,000 ft. to 5,000 ft.). Due to the soaring costs of drilling, successful attempts have been made to apply this technique to deeper wells. The case histories to be discussed in this paper are about deeper wells.

This paper will describe the sizing techniques for field applications using variable frequency (speed) drives (VFDs or VSDs) with electric submersible pumps (ESPs). The field installations will be described along with reservoir and production information. Then the controls available with the VSD's and their uses will be discussed. Finally the various control and transformer settings for different applications will be presented.

The average person driving down the highway past a pumping unit working away in the adjoining field has no conception of the many problems involved in the selection of this unit for its particular job and the constant continuing care that must be expended to keep it doing its assigned task year after year. All of this falls into the province of the oil business with the major responsibility on the production department of each company to keep the pumping units going and the oil coming.

High density liquid corrosion inhibitors have many advantages over conventional inhibitors in problem well treatments. High fluid level pumping wells, low pressure gas wells, high pressure gas wells, flowing wells with packers and wells with static water columns in tubing strings that have been difficult or impossible to treat with conventional inhibitors can now be treated effectively and economically with high-density liquid corrosion inhibitors. These inhibitors cut equipment costs, eliminate emulsion problems, swabbing expense, eliminate need for circulation of pumping wells, and in many cases cut frequency requirements for treatments. High density liquid corrosion inhibitors are available for both "sweet" and "sour" well fluids and for wells which produce a high percentage of water or practically no water from the formation.

The American Petroleum Institute (API) method for rod pumping system design became available in the mid 1960"s. Even after 30 years, questions still arise concerning its utility. This paper examines basic premises of the API method and how these affect accuracy and applicability. A comparison is made with wave equation techniques which are also widely used. It is concluded that the API method is useful and can be applied with confidence as long as underlying assumptions are not violated.

Data from field tests of a new flux-leakage/eddy-current wireline logging tool are presented. This device is used to inspect well casings in place. Images of both the inner and outer surfaces of the casing can be produced using the high resolution data provided by this tool. A real-time signal processing algorithm is available to enhance the raw data. The signal processing algorithm is described, and then several examples of applying the algorithm in different wells are given. Both conventional data presentations and images are shown. The paper gives important details about the tool and some results of testing the tool on well casings which have known artificial defect arrays. It is shown that holes as small as l/8 in. in diameter can be detected. Further, metal loss from as little as 10% of total wall thickness to 100% of total wall thickness can be identified by the tool. In addition to sharpening the resolution of the measurements. the enhanced signal processing algorithm can be used to classify joints of pipe as undamaged to extremely damaged: and. makes it easier to see small defects which are masked by background signal which is due to small scale surface roughness of the non-defected pipe. This pipe inspection device is a cost effective system for determining pipe conditions for repair. Remedial workovers, or adjustments to cathodic protection systems when needed. Usage's such as determining economic value of the pipe in P&A, exact location of perforations or leaks, periodic monitoring in gas storage or injection wells, and pressure limits for well servicing operations.

For most wells that have to be pumped, the conventional crank-type beam pumping unit meets all specifications and is lower in price and maintenance costs. However, in recent years a new unit has become increasingly popular because it has some advantages over the conventional unit. This is the Air Balanced Beam Pumping Unit, which differs from the conventional unit in that compressed air is used as a means of counter-balancing the load on the polished rod. In other respects the air balanced unit resembles the conventional unit in that it employs a speed reducer, cranks, pitman's, beam and Samson post as used for many years on conventional units.

It has been accepted industry practice to utilize continuous measurement in the control and optimization of production facilities, however upstream reservoir and production Engineers are challenged to make similarly important decisions based on little or no downhole data. The development of real-time well monitoring technologies for land-based applications has furthered Engineer's ability to make pro-active decisions based on continuously monitored bottomhole parameters including pressure, temperature and flow. This paper will provide and understanding of the emerging applications of continuous well monitoring related to production optimization, pump control, well stimulation and reservoir development. Casing and tubing conveyed monitoring systems are discussed. Where possible, actual client case studies will be used to quantify the value achieved through utilization of these technologies.

In June 1978, the Carbon/Oxygen (C/O) Log began aiding formation evaluation in the Gorieta reservoir of Johnson Field, a moderately porous carbonate trend in central Ector County, eight miles northwest of Odessa, Texas. Production there is from four separate reservoirs - the Grayburg - San Andres, the Holt, the Glorieta, and the Upper Penn. Until recently, Glorieta development was limited by lack of oil shows in drilling samples, by poor drillstem test performance, and by high water saturations calculated from open-hole logging packages. But, results of the Carbon/Oxygen Log substantially contradict open-hole log interpretations and have led to successful completions in zones previously believed to be wet. Based on these data, eleven wells have been either drilled or recompleted to the Glorieta. The paper will review the history of Glorieta development in the ' Johnson area prior to use of the C/O Log and will briefly discuss the operation of the logging system. It will describe the logging suite now in use, showing a comparison of open-hole and C/O Log interpretations for the same wells. The C/O Log has seen only limited use in the carbonate formations of the Permian Basin, but possible suitability of the log in other West Texas applications is suggested. Information from this project will help other operators the suitability of the logging system in areas where open-ho unavailable or unreliable.

The Formation Micro Scanner (FMS*) tool was introduced commercially in the United States in the Permian Basin in 1985. The tool is the latest development in a four pad, eight button dipmeter type tool, with an array of twenty seven buttons on two of the pads. On pads three and four, twenty seven resistivity curves are then processed into images. Since each image covers 2.8" of the borehole wall, in an 8" borehole 22% of the borehole is imaged with each logging pass. The data is presented on a 1: 5 vertical and horizontal scale or 240" per 100" versus 5" per 100" which is a normal detail logging scale. In the Permian Basin, images have been used extensively in three major areas, High Resolution Reservoir Analysis, Stratigraphic Dip Analysis and Fracture Analysis. With High Resolution Reservoir Analysis, the type of porosity can be determined and if secondary filling of the porosity has taken place. Depositional environments and energy of environments are distinguished, stylolites are detected, and thin bed resolution is possible, all which have never before been identified with normal logging suites. When used for a Stratigraphic Dip Analysis, the data can either be used along with normal stratigraphic dipmeter computations to determine which dipmeter data should or should not be used for stratigraphic computations, or it may be used alone to compute the actual dips of the features seen on the images. Fracture Analysis with the FMS can help distinguish the difference between open and healed fractures, the number of fractures per given interval, types of fractures present (vertical or high angle) and usually if a fracture is natural or has been drilling induced.

Since its introduction to the oil and gas industry approximately five years ago, the consumption of line pipe in thinner than standard wall thickness has grown to the extent that now its utilization in oil and gas lines has become commonplace. Within the last two years this thin-wall concept has grown to embrace oil well casing and tubing as well. This paper will attempt to list some of the current applications of thin-wall pipe as well as the sizes and wall thicknesses available.

Previous advances in biotechnology have provided significant contributions to the oil and gas industry. Enzymes have been used for many years as low-temperature gel breakers. The previous enzyme products were non-specific mixtures of several different, non-isolated enzymes. Degradation by these systems resulted in the creation of polymeric fragments of widely varying size and damage tendencies. Recent biotechnical research has led to the identification of specific enzyme complexes to effect much improved degradation of polysaccharide polymers. The new technique utilizes substrate-specific enzyme complexes to hydrolyze the polymers to as little residue as possible. Neither the crosslinker type nor the degree of polymer derivatization interfere with the ultimate enzymatic degradation of the polymer.

For many, their first introduction to fiber optics was the decorative lamps of the late sixties. A group of optical fibers was tied together at one end and splayed out in a fan at the other. A bright bulb at the tied end illuminated the fibers, and light emerging from the loose end made them sparkle. It created a lovely effect, but had little practical use. Fiber optic technology has come a long way from the glittering lamps of the sixties. During the seventies, the telecommunications industry began to experiment with fiber optics in telephone circuits. From there, the growth of fiber optic applications has been explosive. Fiber Optic application is now becoming commonplace in our homes and businesses carrying not only telephone communications but also data, cable television, internet and security functions to name a few.

Numerous types of pump off control devices have been available to producers and operators since the late 1960"s. Since that time, pump off controllers have proven themselves to be invaluable in reducing lifting costs and increasing pumping system efficiency. This technology has, in general, been applied only in cases where economic justification is assured. Sadly, marginal (or stripper) production does not justify the expense and maintenance of most controllers. Therein lies a paradox - the wells that could economically benefit most from the application of pump off controllers were excluded from consideration due to economic constraints. The need for a simple, inexpensive and reliable POC became abundantly clear. By taking a unique approach to the detection of pump off, D-JAX Corporation of Midland, Texas has been able to reduce the complexity of pump off controllers, making them more reliable and less costly. A large majority of marginally producing wells are now within the economic threshold of pump off controller applications. This paper discusses the required functions and attributes of a pump off controller, proper selection of wells for successful pump off control application and a low cost, reliable means for the detection of pump off. Case studies will show how pump off control has been successfully applied to marginal (and other) producing wells to lower lifting costs, enhance pumping system efficiency and increase profitability.

A recently developed SPC program from Nalco/ Exxon Energy Chemicals, L.P. can significantly increase control of rod pumped wells. The program is applicable to automated pump off control(POC) systems where the controllers communicate with a common host. The program was derived from a need by Amoco to more effectively monitor paraffin deposition on tubulars in deep commingled wells. These wells experienced severe paraffin deposition resulting in costly well repairs. While the treatment method was important, the lack of an effective monitoring tool was critical. Amoco wanted a predictive monitoring tool that would warn them of paraffin in build up before it became a serious problem. Proactive monitoring of this type is one way to add value to automated monitoring systems. We learned that how well a rod pumped well is performing is a function of the data available from the POC and that applying SPC to this data will result in tighter control and improved operating efficiency.

Accurate and timely information is necessary if oilproducing facilities are to be operated properly. The operation of oil-producing properties at the optimum degree of efficiency is rapidly becoming an absolute necessity in the present social, economic, and political climate. The rates and volumes of the oil production, produced water, well test, and injection water are all important parts of the required information. It is not reasonable to expect a high degree of efficiency without this information being available. This paper discusses one phase of the continuing effort to provide this information to the operating personnel in the best possible manner. This effort is in fluid measurement. Several production units were formed in the Slaughter Field in Hockley and Cochran Counties in West Texas in the mid 1960"s; they were placed under waterflood soon after the units were formed. Meters were installed as a part of the initial water injection system. The injection lines were laid in a trunk and lateral system and, therefore, the individual injection-well meters are scattered throughout the field with a central remote readout capability. In the nearly 15 years since this metering system was installed, there have been technical advances in the art of metering, and economic conditions have also changed. A significant improvement in metering technology has been the development of sensing devices which make possible more positive detection of primary signals of low intensity. The economic changes have, of course, been the increased cost of equipment and labor. The cost that we are primarily concerned with is the one which we have the most control over: the cost of repair or maintenance. These two changing factors, coupled with the increasing importance of operational data, brought about the study of the application of the vortex meter as a possible improvement in metering systems.

There is a generally held opinion among the users of subsurface rod pumps that those pumps built to the specifications of API, Spec 11AX, have the following characteristics: 1. Their design is excellent with little need for improvement. 2. Equal quality can be obtained from various authorized manufacturers by simply specifying dimensions and materials in broad generic terms. 3. The individual design of pump parts has little or no bearing on pump performance. The author contends that these opinions are erroneous resulting in millions of dollars of unnecessary expense each year for the repair and maintenance of rod pumping equipment. To prove his contention he traces the history of the standardization program considering industry requirements, standardization goals, and the design options left open to the manufacturer/user team. He then discusses design details of some of the rod pump components that can cause major differences in pump performance and run time. In conclusion it is recommended that users consider all these factors to improve pumping system performance and reduce lifting costs.

The concept of the Area Waste Management Plans (Plan) for use in a company's drilling and production operations is explained. The objective of the Plan is to improve a company's waste management performance by developing appropriate waste strategies and communicating them to the field operations personnel handling the wastes. The Plan provides a process for identifying appropriate waste management strategies in a specified area's operations. These strategies consider current regulatory requirements, company policies, economic and practical factors. Management practices covered in the Plan include minimization, storage, handling, and disposal. Once developed, these strategies are communicated to field operations through a document specifically designed for effective use by field drilling and production personnel handling the wastes. The Plan's objectives, development, content and possible alternative applications are presented. Examples are given from the development of an actual Plan.

Proper matching of artificial lift equipment and technology to the specific problems of specific wells and reservoirs at acceptable cost is a rather sophisticated engineering exercise. Despite our current influx of engineering talent, people fully qualified to design and oversee the best possible artificial lift installations are in short supply. And those who are fully qualified very likely have other demands on their time.

A desire to return to operations in the simpler, single string form, yet maintain multiple zone allowable, formulated by the economic squeeze was the need which created the multiple completion choke assembly. A pressure production base was established as the means of allocating production, but this type of test procedure creates an economic burden which must be eliminated when a well moves to artificial lift status. A review of past allocation means, the new rules which govern multiple completion chokes in flowing and artificial lift wells, and installations utilizing improved producing techniques with pronounced savings are discussed.

A leak in the high pressure packing of a artificial lift system hydraulic pump has the potential of causing environmental pollution, safety hazards, loss of energy and costly clean-up. The subject of this paper is a system that prevents the product being pumped from becoming exposed to the atmosphere and surround areas. The technology to be described transfers the pressure of the product being pumped to a sacrificial barrier fluid of known characteristics. When the seals wear sufficiently to leak, only the environmentally friendly fluid leaks to the atmosphere. The technology can be built into new equipment or be retro-fitted to pumps in service with the proper modifications and sealing assemblies. The paper includes photographs of the Hydro-Balanced Stuffing boxes for sucker rod pumps and a diagram of the artificial lift pump improvement. The presentation will include slides and graphics of the Hydro-Balanced Packing System.

The purpose of artificial lift equipment is to do work by adding extra power to the produced fluid so that the fluid will flow to the surface. The power added lifts the produced fluid to the surface at a rate higher than the well power can provide. The power is added to the fluid by some type of downhole pump or gaslift. "Artificial Lift Efficiency" is a way to calculate how effective a particular type of lift equipment is in adding power to lift the fluid. In the literature there are many definitions of artificial lift power efficiency, but there is not one particular accepted equation. Reference 1 lists and reviews a number of references, which provide a variety of expressions calculating artificial lift efficiency. Also this reference compares a number of ESP vs. Beam Pump wells with electrical or power efficiency. However, in the paper it is shown that the definition of efficiency that was used in that study is subject to some unexpected variations if the surface pressure or amount of gas produced through the tubing is varied. Because of this, the definitions of artificial lift efficiency are reviewed and a standard equation is recommended.

When evaluating artificial lift in a CO2 flood, certain factors must be taken into special consideration. This statement is especially true if the reservoir is a sandstone without H2S. Such conditions exist at Postle Field in the panhandle of Oklahoma, making it a field of unique nature. Under normal considerations, when CO2 is injected, it mixes with water and produces a weak carbonic acid. If the reservoir is a carbonate, the rock will buffer the acid. If H2S gas is present, it also offers benefit and provides further buffer to the acid. At Postle Field, however, neither is
present. This field produces out of the Upper Morrow Sandstone which contains no carbonic cementation. In addition, it is an extremely corrosive field, which makes artificial lift very complex and dangerous. Postle Field has a robust number of wells that have either been lost or in danger of being lost, due to problems created by corrosion. This paper will discuss what is taken into consideration when designing artificial lift for the corrosive nature of Postle Field.