It is becoming more important, due to greater depths, higher temperatures, and increased volumes, that the most dependable and economical pumping equipment be installed to produce oil wells at this time. It is important that the operator be fully aware of the advantages of the electrical submergible pumping equipment and make efficient use of it. This paper will bring out these more important advantages. When these advantages and operating techniques are understood and utilized by the operator, one of the most economical methods of well production can be achieved. The use of the gas separator to increase the efficiency of the pump and to eliminate the problem of gas-locking will be discussed. The various ways centrifugal, submergible pumping equipment can be used to produce oil wells and in waterflood operations will be covered.

Polyacrylamides hydrated in hydrochloric acid and crosslinked with iron-based ions have been utilized for a number of years as in-situ divertors in the stimulation of extended-length carbonate zones. A significant improvement to this process has been developed, field-tested, and placed into general use. Crosslinking the polyacrylamide with a zirconium-based metallic ion has proven to be an alternative with a number of advantages over existing systems. Dependency of the system on iron derivatives for crosslinking is eliminated, the precipitation of ferric or ferrous compounds that can cause sludging or stabilize oil/water emulsions is minimized, and viscosity degradation of the in-situ crosslinked acid is not completely dependent upon the rising pH of the acid as it spends. An external breaker is added to the system as an aid in apparent viscosity reduction. Case histories are briefly reviewed. Treatment design data, including fluid friction pressure curves and rheologies are presented for use by the practicing engineer. Input parameters suitable for the most common 3-dimensional fracturing and matrix stimulation modeling simulators are included.

It has been documented in field test results that in many cases a production increase can be obtained by replacing a steel sucker rod string with a fiber-glass and steel sucker rod string. (2) While these tests have demonstrated the value of fiberglass sucker rods, the beam pumping systems were still fairly inefficient because the pumping units that were being used were originally designed for use with steel sucker rods. A more efficient beam pumping system has been developed that uses fiberlass sucker rods in conjunction with a pumping unit that was designed to take greater advantage of the properties of fiberglass sucker rods. (3) This paper discusses the unique characteristics and history of fiberglass sucker rods, and examines how this new pumping unit takes advantage of the properties of fiberglass sucker rods to produce a more efficient beam pumping system.

A high quality cement bond between casing and wellbore is an environmental and economic imperative for the duration of a well. A strong cement bond provides zonal isolation and prevents gas migration, gas entrapment and excessive water production. The growing public concern about possible gas migration to fresh water or to the atmosphere has further highlighted the importance of achieving the best possible cement bond. A chemical preflush prior to primary cementing is an inexpensive and effective method to help ensure a quality primary cement job. Ideally, the chemical preflush should be multi-functional and not only remove drilling fluid residue but also provide other features such as: improve fluid loss control, improve water wetting of surfaces prior to cementing, and prevent or aid in the prevention of cement fallback. To achieve all these features, it is common practice to run a sequence or blend of chemicals to adequately prepare the wellbore for cementing. This paper discusses a single-component product built on sodium silicate that can provide all of the aforementioned benefits. Specific focus is directed towards the interactions between surfactants and sodium silicate in a flush

Separating water produced in conjunction with crude oil has been an ever increasing problem since Drake's first well. As refinery capabilities grew more complex and pipeline companies became more aware of the problems associated with water, their demands to lower the water content of oil expanded to those we know today. The process equipment arm of the petroleum industry has always reacted to these needs with ever growing efficiency. This paper reviews past efforts and introduces one of the latest advancements in crude oil dewatering, documents its state-of-the-art applied technology, and reports its resultant efficencies.

The industry has developed methods to improve the sweep efficiency during EOR processes. These methods include the use of certain patterns, as well as horizontal or deviated wells. The goal of these processes is to create an even movement of injection fluid across the reservoir. Special chemicals have been used to divert the injected fluid to eliminate channeling and to improve sweep efficiency. This paper will present a new methodology to modify sweep patterns to positively impact recovery. The technique that is presented creates a mechanical barrier to flow by fracturing the formation at a strategic location. We illustrate the potential productivity increase of producing wells as a result of enhancing the horizontal and vertical sweep of the hydrocarbon. The paper also demonstrates that the combination of the barrier fractures
with other developed tools, such as inflow control devices and internal control valves, would further improve the productivity and economics of the system

The Spraberry trend of west Texas is a low-porosity naturally fractured reservoir, traditionally completed in the Upper Wolfcamp carbonate, Dean sand, Lower Spraberry sand, and Upper Spraberry sand zones. The overall interval is from 1200 to 1500 ft. thick, with completions encompassing from two to four stages. In all cases the wells require large hydraulic fracture treatments to produce economic quantities of oil and gas. The most common method of perforation selection involves correlating from well to well using cased hole gamma ray/neutron logs and drilling time. The large majority of the wells in the Spraberry trend have been perforated using this technique. The small minority of wells that have used openhole data have relied heavily on basic porosity and water saturation data to select perforations. Recent data suggest that production can be improved significantly by using VOLAN*, CFI*, and FracHite* data to select the perforated intervals. A group of 10 Dean/Wolfcamp wells that used the combination package of VOLAN/CFI/FracHite had a 103 percent increase in initial oil potential over 11 offset Dean/Wolfcamp wells that used basic openhole porosity and water saturation data. In addition, the well group with VOLAN/CFI/FracHite data produced 73 percent more oil over the initial four months of production than the offset wells. A discussion of the methodology, follows, along with the production results of the 21 wells in the study.

Multilateral horizontal wells have been used as an approach to further improve production and injection volumes. As a result, very often the steep hyperbolic decline seen in a single lateral well is reduced. The first approach used was with a milled casing section in which several laterals are drilled off a cement plug. Subsequent laterals are then sidetracked off the main laterals drilled. These laterals are 4 314 inch openhole with no liners. Reentering these laterals is costly when doing initial stimulation work for completion. Considering the future need to clean out fill or other precipitants with a bit and also to restimulate, a lower risk well design was desirable. With the help of Weatherford Enterra, a system designed using a permanent packer and retrievable whipstocks was used to address the problems and costs of finding multiple laterals. The system has considerably reduced the amount of time it takes to locate each lateral and greatly improved the likelihood of doing so at a later date.

The Permian basin of west Texas is known for its low permeability reservoirs, earning it the reputation of "hard rock country." wells completed here require A significant percentage of the hydraulic fracture treatments in order to produce economic quantities of oil and gas. The hydraulic fracture treatment can represent a significant portion of the total well cost. In addition, the effectiveness of the treatment can be critical to the economics of the well. Too small a treatment can leave valuable hydrocarbons in the ground. Too large a treatment can be equallyinefficient and possibly ruin the well. Knowledge of the rock elastic properties and in-situ stress distribution is critical to determining the induced fracture geometry. With full sonic waveform data now available, the dynamic elastic properties of the rock can be directly measured. Poisson's ratio (v) can be directly obtained from the shear and compressional transit times. From the v/(1-v) relationship the horizontal stress component of vertical overburden stress can be obtained. When this is combined with pore pressure and bulk density data a relative closure stress value can be obtained. The final product is called the FracHite* log. As of this writing, over 450 wells have been evaluated with this technique. Several single-zone and multiple-zone field cases are presented here to illustrate the applications of the technique in the Permian basin. In addition, a 2D hydraulic fracture model is used in conjunction with actual decline curve data to illustrate the specific benefits of accurate hydraulic fracture height data. The case study utilizes data from a representative producing San Andres well in Ector County. An additional item of importance is the orientation of the hydraulic fracture. This is critical to designing an efficient drainage pattern in a field. It is now generally accepted that the hydraulic fracture follows a two-wing pattern dictated by the natural stress distribution in the rock. With the eight button Dual Dipmeter* and the FILMAP presentation this natural stress distribution can be mapped with an unprecendented degree of accuracy. the Dual Dipmeter, Nine Spraberry/Dean wells were evaluated using and the results are presented on a map of Midland and Martin Counties.

For maximum profits in rod pumping operations the efficiency of the pumping system must be maximized, this can only be achieved by finding the optimum pumping mode for the required liquid production rate. These principles are used in the paper by presenting a case study on improving rod pumping operations. The project reported was conducted in a mature onshore field with 70-plus rod pumped wells. An extensive measurement program involving more than 50% of the wells was set up and pumping parameters were measured with a portable computerized system. The detailed evaluation of measurement data facilitated the detection of general and specific problems. With the aim of improving the field-wide profitability of pumping operations, an optimization of each well's pumping parameters was made. Calculation results showed that a field-wide power saving of about 17% can be anticipated if all wells operate at their most economic pumping modes.

Carbonate formations are often stimulated by hydraulically fracturing the zone of interest with reactive fluids, most commonly hydrochloric acid. The productivity increase of the oil and gas wells where this stimulation approach is utilized, is often much less than predicted by the pretreatment design. This paper will address the problems and difficulties of properly designing an acid fracturing stimulation treatment, and will offer new techniques and alternative fluid systems that allow better designs for this type of stimulation. These new methods and fluids have recently been applied to achieve extended fracture penetration of live acid into carbonate formations, allowing higher sustained production. Results of treatments where the new designs have been utilized throughout the Permian Basin will be included as case histories.

Increase the return of your investment! Naturally, everyone is interested in doing this. The object of this paper is to discuss some recent developments of accessories which may be adapted to your present sucker rod pump which will make it better suited for the well condition. All of these accessories may be adapted to most of the conventional sucker rod pumps, and will increase their efficiency or service life, thus increasing the return on your investment.

As a result of increasing emphasis on cutting waste, streamlining operations and improving recoveries, the use of the short cycle adsorption unit has become a widely accepted method of processing gas streams.

The production of high gas liquid ratio (GLR) wells has been a problem for oil producers since the first sucker rod pumping systems (SRPS) were installed. This paper examines three key factors in improving SRPS efficiency in high GLR wells. These include pump design, rod string stability and field operations. Although pump design and field operations are well documented, an attempt is made to clarify these areas. Also, new light is shed in the area of rod string design with special consideration of rod buckling and its associated problems.

This paper describes field implementation of a newly-developed downhole injection @I-II) tool for same-well-bore, simultaneous-gas-production-and-water-disposal, for water drive oil and gas formations with water coning problems. The method enhances the production rate of water-free gas while minimizing disposal cost and eliminating problems associated with water disposal. (Fig. 1)

The accurate determination of residual oil saturation is of critical importance in evaluating the feasibility of applying an enhanced recovery process in a specific reservoir. The economics of the new improved recovery processes are extremely sensitive to the residual oil saturation in place at the beginning of the project and to the conformance expected to be achieved within the project area. This means that both the amount and the distribution of oil remaining in place must be determined to adequately evaluate the potential of the venture. The only accurate means of determining the residual oil saturation is to measure it in situ within the reservoir zone of interest. In recent years, several methods have been developed to provide this measurement, including analyses of cores cut with a pressure core barrel, various advanced logging techniques, and the single-well tracer test. Each method has certain advantages and limitations, but field experience has shown that some methods are clearly superior to others. However, for some reservoir situations, one method may not provide all the information required to completely define the distribution and amount of remaining oil. These cases might require the application of two or more methods combined with an analysis of all available reservoir data. This paper will briefly summarize several procedures for determining residual oil saturation and. as pertinent, outline the advantages and limitations of each technique. The single-well tracer method will be described in more detail in terms of two recent field applications.

Incident at Morales involves a variety of ethical issues faced by a company that wants to quickly build a plant in order to develop a new chemical product to gain a competitive edge over the competition. This 36 minute video developed and distributed by the National Institute for Engineering Ethics will be shown.

The accumulation chamber is an efficient method of oil production by gas lift. The fundamental purpose of the chamber is to provide additional storage space in the well bore during intermitting gas lift operation. Various formulae are offered for the calculation of chamber design. It is shown by theoretical analysis, supported by field data, that the use of the gas lift chamber principle improves production.

In the reaction of formation rock with acid, as in a matrix acidizing treatment, varying quantities of insoluble fines are released or otherwise dislocated by the flow. Also, normal reservoir flow can break or dislodge fragile clays and minerals present on the pore linings. If allowed to settle and accumulate, these fines have the capability of plugging pore throats when disturbed in mass upon the return flow of the treatment and formation fluids. The addition of a silt suspending additive to the acid used for treatment will prevent this accumulation by keeping the fines distributed in this fluid, thus preventing plugging while removing them from the formation. A silt-suspending system that uses an electrostatic repulsion approach to fine suspension is discussed. Laboratory work describes the system's properties in relation to oil reservoirs and field data shows the system's usefulness. This treatment has been successfully used in well workovers to remove existing clays, fines, and precipitated solids. Production data on this aspect is presented.

A case study was conducted on San Andres Formation wells to evaluate the benefit of focused efforts to optimize hydraulic fracturing treatments for improved well productivity. The application of conventional fluids and techniques had provided lower than expected post-treatment productivity and a rapid decline rate, suggesting that fracture conductivity was less than optimum. Several recently introduced hydraulic fracturing technologies were combined to develop an integrated treatment design and application package to improve well production. Included among these were real-time fracture treatment analysis, advanced mini-frac analysis, the use of state-of-the-art fracturing fluid and breaker chemistries, and the application of resin-coated sands and forced-closure techniques. Average incremental production was significantly increased through application of the new technologies. The effectiveness of the modifications in design, chemistry, and application is clearly demonstrated by the production improvements.

In the present state of the oil and gas economy, operators have been searching for ways to increase production and cash flow with no gamble and with an AFE expenditure that gives their money back and a good return on their investment the first year.Operators are finding that one sure way to increase production and cash flow on producing wells is to relieve the RESTRICTING BACK PRESSURE on the producing formation on wells which respond to this technique. This restricting back pressure is caused by a combination of several things; a direct result of the sales line pressure; the pressure required to operate the separator; the line friction from the separator back to the well head. These flow lines vary in length and the longer the flow line and the terrain they follow, the more back pressure you will find at the well head. The final results of this back pressure translates all the way down to the face of the formation and restricts its ability to give up oil and gas. Pressure requirements to operate an individual lease may vary, but the negative effect of production is the same - IT IS RESTRICTED.

The increasing recognition of Plunger-Lift as a viable method for producing many wells, has brought a number of changes to the technology involved. The importance of proper plunger-lift performance criteria (as reported in an earlier SPE paper) has been recognized and steps taken to incorporate this information into modern day control systems. This paper discusses the usage of plunger velocity in establishing operating cycles for gas wells and for oil wells. When used in conjunction with state of the art electronic microprocessors, the results are increased Production, extended economic limits, less downtime, and many others. This has been proven to be the case in both conventional and slim-hole wells. Primary areas of discussion are: 1. Relativity of plunger velocity insofar as efficiency is concerned. 2. Standard approach historically taken to achieve maximum production. 3. New software design that automates cycle changes while increasing production and reducing both man hours and down time. 4. Test results and case histories.

Removal of emulsified oil from waste water is receiving renewed attention in light of best practical control technology and treatment level requirements. This paper presents a discussion of the induced-gas flotation process as a method for cleaning waste waters by removing suspended contaminants using, froth floration. The origin of the process is briefly reviewed and a comparison is made to dissolved-air flotation showing that the two processes have both similarities and differences. A method of inducing and dispersing gas bubbles into water with individual cell mechanisms is discussed. Consideration is given to both the hydraulic and chemical characteristics of the stream. The complete flotation machine incorporating multiple cells in series is assessed from the mechanical design standpoint. The operation of induced-gas flotation equipment is explained. Consideration is given to the interrelationship of various design and operational aspects of this process. Both the importance and the limitation of chemical treatment additives are pointed out. A bench test method for selecting chemical treatment is discussed with a critical review of its ability to predict scale-up unit performance and the chemical formulation and volume requirements. Review of past oilfield experience with induced gas flotation machinery, shows that this is a viable method for cleaning produced water of suspended oil and solid particles.

Separation of oil and water has been important in crude oil production historically. Some oils and produced brines do not mix with enough stability to seriously complicate handling. Water in oil emulsions are more common than the oil in water type, often called "reverse emulsions" or "O/W"S". We will see, however, that there are problems in clarifying produced water, or more specifically removing trace amounts of suspended oil and solids from this water. This discussion will bear upon resolving the more stable dispersions of oil in water that are encountered in oilfield production practice. Therefore, it will concern clarification of that water by several methods including the induced gas flotation process (IGF).

The most valuable assets held by any company are the men and women who do the work. The job of properly defending these assets equals, or transcends, all other responsibilities of supervisory personnel. Responsible industrial organizations recognize the economics involved in protecting employees and are seeking individuals with ability to promote safety.