The Bakken, one of the last giants to be discovered in North America, extends from Montana through North Dakota and into Saskatchewan and Manitoba provinces in Canada. The USGS, in its latest study published in April 2008 (USGS 2008), estimates that the undiscovered US portion of the Bakken Formation holds 3.65 billion barrels of oil, 1.85 trillion cubic ft of associated gas and 148 million barrels of natural gas liquids. Being classified as an oil play dependent on full well-cycle margin efficiencies to increase profitability, technology will be a main driver in the success of the development of the Bakken. Two technologies that have been critical to the current success of the Bakken are: horizontal drilling and hydraulic fracturing. Operators typically drill on 640 or 1280 acre spacing. Typical 1280-spaced lateral lengths are over 9,000 ft, at a total vertical depth (TVD) of 9,000 ft (Miller et al., 2008). Once extended reach horizontal drilling was proven reliable, attention was turned to optimizing production from these laterals. This paper will present an enhancement to an existing technology that enabled the operator to vastly increase the effective flow area created by staged hydraulic fracturing. In the process of bringing this technology to market, both the service company and the operator agreed that the true value-adding function was the process that enabled an expediting of the product from concept to implementation. The development of new technology by service companies is critical for operators to expand their operations, drive operational efficiency, and work profitably in ever harsher environments that are lower on the resource triangle (Fig. 1) (Masters and Grey 1979). Product development is sometimes performed by service companies with requirements gathered from several operators, while at other times service companies will develop products specifically to meet the needs of a single operator. This paper will describe a synthesis of these processes, and the design and testing hurdles encountered, for a project that met the needs of both a single operator and the service company. The product is expected to provide continued benefit throughout the Bakken drilling and completion campaign for this operator, as well as provide a solution for the broader market for the service company. As a result of this collaborative effort, a new product was conceptualized, developed, lab tested, field tested, and taken to market in an accelerated time frame. Fig. 1 Resource Triangle.

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Unconventional reservoirs require innovative completion techniques and technology to become more economical. Formations vary drastically in lithology, lateral lengths, completion methods, and financial drivers. One of the most common techniques is the ‘plug-n-perf’ method. In the Eagle Ford, long-string completions are the norm, with the production casing cemented in place along the horizontal section and up the vertical section, providing isolation between frac stages and from other formations above and below the zone of interest. The Eagle Ford shale is a formation that produces gas, liquids, and oil, depending on the area in South Texas being drilled. Operators are looking for ways to reduce cost and gain efficiencies when completing wells in unconventional reservoirs. One way of reducing cost is eliminating coiled-tubing-deployed perforations for establishing reservoir communication on the first stage of multistage frac operations. Technology has been developed which provides operators the option of placing a pressure-actuated valve above the shoe track, allowing for standard cementing practices. The new valve provides operators the ability to pressure test the casing and, through the use of applied pressure from the surface, activate into the open position. Once opened, information about the reservoir can be gathered that will influence the frac design before assembling the required pumping equipment. This paper presents multiple case histories showing different applications of the cemented pressure-actuated valve. The development history, reliability, and inherent accuracy are presented. This interventionless access technique has been proven effective in the Eagle Ford and Haynesville formations and is applicable in other unconventional reservoirs requiring multistage hydraulic fracturing.

The rubber-sleeve core barrel was developed to improve core recovery from unconsolidated sands, where it is most difficult to obtain cores with conventional barrels. The use of a rubber-sleeve core retainer, together with other departures from usual design, has required a considerable amount of testing to prove its operability. Tests run in shallow experimental holes and in drilling wells in the U.S. and Venezuela have, to a large extent, proved the operation of the barrel. Internal mechanism troubles, such as sandbinding of the sleeve, have been largely overcome. Cores have been recovered from completely unconsolidated sands where conventional coring has almost been abandoned because of poor recovery. In addition to retaining the core until brought to the surface, the barrel gives a "packaged-as-cut" core, which is convenient for handling and transportation. In the initial work, drag blade cutters, roller cutters, and tungsten carbide insert cutters were used for cutting unconsolidated sands. Further bit head development is presently being conducted using diamond heads in unconsolidated sands where shales, hard sands, and limestones are encountered in adjacent formations. This work should render the barrel capable of cutting and recovering most types of formations, possibly including broken and fractured formations. This development is being carried on in cooperation with a diamond bit manufacturer. Introduction For many years the oil industry has needed greater recovery of cores from unconsolidated formations. Conventional equipment has been used to core unconsolidated sands with little success. Specifically, a core barrel was needed which would recover unconsolidated sands in a condition that would give useful reservoir information. Development of the Rubber-Sleeve Core Barrel Basic Requirements of Unconsolidated Sand Coring The basic need was defined as a core barrel that would obtain a continuous unconsolidated core with sand grains in place as deposited in the formation. A preliminary survey of coring equipment and search of the literature pointed out the weaknesses of conventional core barrels. Laboratory tests using unconsolidated sand in a metal tube simulated actual sand movement into the care barrel during conventional coring. In conventional barrels the core sometimes crumbles and bridges, or fails under compressive column action, becomes oversize, and wedges against the walls of the inner barrel.