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A common trend in our industry is to minimize gel concentrations and utilize the lowest viscosity fluid availah to place proppant. Barrett Resources Corporation has found, for lenticuiar microdarcy formations, that one of the keys for success is enhanced proppant transport, This is achieved incorporating stable gels which maintain greater than 1000 cps viscosity at bottomhole static temperature for the duration of the treatment.

The Cornell Unit is a 778.2 m2 (1,923 acre) waterflood project in the Permian, San Andres, dolomite reservoir located in the Wasson Field, Yoakum County, Texas. The Unit currently consists of 66 producing wells and 26 injection wells. Production is approximately 1430.9 m3 (9,000 barrels) of oil per day, 1367.3 m3 (8,600 barrels) of water per day and 240,693.2 m3 (8,500,OOO cubic feet) of gas per day. Daily injection averages 4133.7 m3 (26,000 barrels) of water.

San Andres producers in several areas of Gaines County, Texas are limited on stimulation injection rates due to the proximity of potential water producing intervals. The San Andres is a dirty dolomite formation with a bottomhole temperature of approximately 135_F. Usage of acid to stimulate the formation is desirable, but given the low injection rate restrictions, diversion and penetration of the acid into the formation are difficult to accomplish. Prior treatments using rock salt for diversion resulted in most of the salt falling into the rat-hole.

The CO2 foam fracturing fluid provides a gas drive to assist removal of the treating (load) fluids after the proppant has been placed in the formation, establishes permeability to gas within the formation volume that has been saturated by load fluids, and minimizes the actual water volume that is required to place a given volume of proppant in the formation. Due to the high density of the liquid CO2 mixture, the CO2 foam can be utilized on deep, high pressure formations without experiencing prohibitive wellhead treating pressures.

The subject matter of this paper will describe Binary foam fluids, their advantages and how they have been applied to increase production in various tight gas sands in Southeast New Mexico. The paper will include a discussion of the formations stimulated, production results, and typical treatments for tight gas sands. Furthermore, the paper will include comments on Binary foam design utilizing three dimensional fracture simulators and considerations for workover candidate selection.

Fracturing designs are generally based on information from 2D simulators, 3D simulators, field experience, or previous designs. Once a fracturing job is designed and a fracturing schedule is established, the job is usually pumped according to design without any changes. Because of such inefficient planning and procedures, millions of dollars are wasted each year on fracturing jobs that fail to provide the expected results. Preplanning and real-time analysis are key factors for successful hydraulic fracturing and increased hydrocarbon production.

Corrosion of injection equipment is a common problem in CO2 miscible injection operations. The two basic mechanisms by which this corrosion occurs are from internal corrosion caused by holidays in the injection tubing coating as well as from external corrosion caused by CO2 invading the tubingcasing annulus through minute seepages in the downhole injection equipment. Unfortunately, these problems are both common and costly.

TEXACO U.S.A. has successfully installed an automation system which provides distributed remote control and monitoring of the entire array of producing operations at the Wharton and Robertson Waterflood Units in Gaines County, Texas. A preliminary economic analysis of the project indicates that the benefits attained have exceeded expectations. Microprocessor based Remote Terminal Units (RTU's) are used to detect and report alarm conditions and operating data to a Master Terminal Unit (MTU) located in a field office on the Wharton Unit.

A liner is probably the most critical string of pipe set in a well. One of the most common problems encountered in liner cementing is the migration of gas in the annulus during the cementing operation. This can lead to a leaky liner top and a subsequent remedial squeeze job. By using proper cementing techniques and materials, including mud removal procedures, gas migration can be minimized and the need to squeeze liner tops can be reduced. Recently, several liners were set in wells in Lea County, New Mexico, in which different drilling conditions and problems were encountered (Table I).

Sand, Iron Sulfide, Frac Sand, and other particulates produced with the fluid often cause sucker rod pumping problems that shorten sucker rod pump runs to unacceptable times, or actually prevent successful use of sucker rod pumping. Common sense methods of successfully dealing with these particulate problems will be covered as will developments in sucker rod pumps for successful particulate production.

When dealing with cementing operations with problematic formation issues, achieving satisfactory top of cement (TOC) is essential. A central Texas operator encountered zonal isolation challenges that resulted in inadequate TOCs. One of those challenges was achieving a density both above the pore pressure and below the fracture gradient. In some wells, this density window was as narrow as 0.02 to 0.04 psi/ft. Karsts and tectonic-fractured formations exist in this field, which often result in uncovered zones and TOCs at unacceptable levels.

Sucker rod connection failures seem to be a problem to some operators, while others do not seem to have the same problems. The connection should be the strongest link in the sucker rod string while the rod body should see more failures. There are three main classifications for the connection failures. These are: manufacturing discontinuities or defects, mechanical damage (including handling and make-up procedures), and loss of displacement (LOD).

Sucker rod coupling friction values are used by rod design software to calculate rod loads for bare steel tubing on steel couplings. The friction values for sucker rod couplings on HDPE lined tubing are not yet known or defined. Therefore, rod load calculations in HDPE lined tubing are problematic. Tests were performed to compare the coupling friction in HDPE lined tubing compared to bare steel tubing at various temperatures and side loads. The objective was to find the drag ratio of rod couplings on HDPE lined tubing to that of bare steel tubing at various temperatures.

After consideration of all component parts in a sucker rod pumping installation, it is believed that the sucker rod string most directly affects the action and performance of the entire system. Sucker rod behavior, in transferring the forces and loads that are involved, determines the action of the subsurface pump. The load imposed on the surface equipment are attributed directly to the inherent characteristics of the sucker rods.

It is important to know the cause of sucker rod failures so that the cause can be eliminated or guarded against. This paper presents numerous illustrations of the most common forms of sucker rod failures and explains the cause of these failures. Corrosion is the greatest cause of sucker rod failure and the bulk of the illustrations are of sucker rods that have been damaged by corrosion. A brief description of the basic corrosion process is included.

The most common type of sucker rod failures (pin failures) can be reduced by application of load range effects. This paper introduces a simple graph which can be used as a guide to limit peak loads based on load range for increased sucker rod service life.

There are very few papers that present the actual fatigue data for various grades of sucker rods from a variety of manufactures. This paper will provide information on the testing being conducted by one sucker rod manufacturer and the performance of high strength API D grade rods versus non-API extra high strength rods for air fatigue in rotary bending tests. Additionally, information will be provided on the relevance of these results and on the next phases of fatigue testing that is being planned.

This paper discusses the history of rod guides, early attempts in their development, types of guides presently available, a study of the proper use of guides, and a recommended procedure for placement of guides.

This presentation will provide a review of published information where sucker rod lift has been used to produce highly deviated and horizontal wells. Additionally, some useful recommended practices from equipment suppliers will be included on design, selection, and changes to consider for rod lift equipment when used to produce horizontal versus vertical wells.

Most sucker rod pin and coupling failures are considered to be related to loose couplings. Correct pin prestress offers the best way to prevent loose couplings and the "circumferential displacement" method offers the best way to achieve correct pin pre-stress.

This paper discusses the many types of balls and seats that the industry has to offer for varied well conditions, and also explains the proper use of plungers, barrels, tubes, cages, and other accessories. Pump parts destroyed by corrosion and abrasion are displayed, as well as sample pumps constructed to resist such attack.

Presentation will cover care and handling best practices for a sucker rod pump from the pump shop to the well bore and introduce a new tool for safely lifting a sucker rod pump from horizontal to vertical at the well head. For years, long and heavy insert pumps have been lifted into the vertical position to be run into the well by various means, some causing damage to the pump and contributing to failures. In most cases this process places undo stress on the rig crew, as they have to support the entire weight of the pump while it is lifted and it places them under a suspended load.

One of the principal causes of subsurface failures is corrosion. Corrosivity of well fluids is primarily related to hydrogen sulfide and/or carbon dioxide gases in the produced water. Optimum utilization of corrosive-resistant materials for component parts of sucker rod pumps has been the more economical practice in Exxon's operation as compared with the use of corrosion inhibitors and less expensive metals. Past performance of pump part metals was studied to provide guidelines in upgrading the pump part metallurgy.

Sucker Rod pumping as it is used in today's oil field, evolved from the waterwell wooden sucker. Early history includes rope used for lifting water in irrigation systems. Increasing rod string performance lift through manufacturing quality control, proper string design, correct handling and control of environment.

For more than ten years the Petroleum Industry has used and benefited from a Reliability Information and Failure Tracking System for electrical submersible pumping (ESP-RIFTS). More recently another RIFTS system for progressing cavity pumping (PCP-RIFTS) has proven to be beneficial to participating members. At the 2010 Sucker Rod Pumping Workshop, discussion started about developing a RIFTS project for sucker rod pumping. This is now about to become a reality. The RIFTS systems collect and store information on pumping systems and system failures.