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Want more production from a shale well? Consider lining up the perforations. A handful of speakers at the recent SPE Hydraulic Fracturing Technology Conference talked about improved fracturing results with oriented perforating—shooting the holes at the same place in the casing, often the top. This breaks from designs that arranged the holes in a helical pattern with each charge angled 60° from the previous one. “We did see indications we are getting better production from oriented perforating,” said Blake Horton, senior completions engineer for Ovintiv (SPE 204177). Production gains were also reported by ConocoPhillips which compared production from similar wells with and without oriented perforating. The analysis was designed to filter out differences in the geology, drilling, and completions. It concluded the value of the added production far exceeded the $20,000-per-well cost of installing the assembly, including a weight bar to tilt the perforating guns into position. “That’s less than the undiscounted value of 400 barrels of oil. An internal study indicated that ConocoPhillips improved estimated ultimate recovery (EUR) by a minimum of 5% when using high-side-oriented perforating,” said Dave Cramer, senior engineering fellow at ConocoPhillips and an early advocate for the method. “For an initial choked flow rate of 1,000 B/D, the payout on investment is 10 days or less,” he said. Ovintiv declined to provide a number, but Horton said ConocoPhillips’ estimate is within Ovintiv’s range based on similar comparisons of wells with and without oriented perforating. That number is at the low end of the estimates offered in discussions about oriented perforating performance at the conference. Higher estimates are questioned by those who doubt the test results can be sustained when the method is scaled up. What was certain is the number of users is rising and includes names such as Shell and Chevron. “We found that oriented perforating definitely helps to treat all the clusters,” said Jon Snyder, a staff completion engineer for ConocoPhillips who presented the paper, adding, “by oriented perforating we mean that when we are perforating, we aim for the high side of the wellbore” (SPE 204203). When Horton polled the audience at a recent talk, more than half of the respondents said they were using gun systems designed to orient the perforating charges at a target angle. “A year from now, few people will not be doing oriented perforating; the advantages of it are clear,” Cramer said. He has been promoting the idea within the company for years with mixed acceptance.
Abstract Hydraulic fracture initiation can be a challenging issue for fracturing deep and tight gas reservoirs, which generally requires a high breakdown pressure for clustered perforation hydraulic fracturing treatment. Oriented perforation represents a potential solution to alleviate this issue, which can not only lower breakdown pressure but also deliver a better oriented fracture geometry. In this paper, we present a new strategy to tackle this issue, which includes a framework to calculate the breakdown pressure, optimum perforation direction, and a new perforation cluster layout design. The optimum perforation direction is defined as the one, along which hydraulic fractures can be initiated with the lowest breakdown pressure for a perforation cluster. It can be used to control the perforation device rotating and fired at the right direction in subsurface. Further we present a new perforation cluster layout design, which can alleviate the near wellbore fracture tortuosity and deliver a better fracture initiation when it is aligned along the optimum perforation direction in the subsurface. The two parts of the strategy working together, fracture initiation from a perforation cluster can be achieved a lot of easy than using the conventional perforation method. This new perforation strategy can further alleviate the near wellbore fracture tortuosity, minimize fluid flow restriction and reduce pressure friction loss during hydraulic fracturing treatment. Otherwise multiple and reoriented nonplanar fractures originated from the wellbore perforation cluster likely lead to a premature screen-out, which can negatively impact fluid injection to achieve a desired stimulation performance. Hydraulic fracturing treatment in deep and tight gas reservoirs can be improved through the following actions: calculating breakdown pressure and optimum perforation direction, using new perforation cluster layout design, and aligning the perforation cluster in the optimal direction in subsurface.
Abstract Analytical calculations have been carried out on theeffect of casing perforations on the productivity of wells, and formulas havebeen derived for general types of perforation patterns. The numericalcalculations, however, show that the resultant well productivity is essentiallyindependent of the perforation pattern, but is determined mainly by the totalperforation density. thus, for example, for a density of three perforations perfoot of casing the well productivity will be cut to one third of that of theuncased well for a perforation radius of 1/8 in., and to approximately one halfof a perforation radius of 1/4in., regardless of the detailed manner in whichthe perforations are distributed over the casing surface. the analytical theoryis also extended to included wells completed with slotted liners. it is showthat the reduction in productivity due to such liners will be relativity smallas compared with that due to perforated casings. Introduction The increasingly important role being played byproductivity factors of wells in determining well potentials and in the generalevaluation of producing formations lends interest to the analysis of all thevarious factors that may influence the productivity of a well. In recent papersthe results have been given of theoretical studies made to determine the effecton the productivity factors of a well of the gas-oil ration of the productionand the connate water within the sand. These have served to show that both ofthese factors may, under suitable conditions materially reduce the effectiveproductivity factors below those that would be anticipated on the assumptionthat the wells produce homogeneous fluids. In this paper will be presented the results of theanalysis of an entirely different factor influencing the productivity of awell.This refers to that resulting from the increased use of the methodof completing wells by setting casings opposite all of the productive strataand then gun-performing the particular zones of immediate interest. Thepractical success of this method of completion would appear to be an answer tothe question as to whether it seriously reduces the well productivity ormaterially cuts down the ultimate oil recovery that may be derived from theproducing section.
Use of Oriented Perforation and New Gun System Optimizes Fracturing of High Permeability, Unconsolidated Formations
Soliman, Mohamed (Halliburton Energy Services) | Dupont, Richard (Halliburton Energy Services) | Folse, Kent (Halliburton Energy Services) | Mason, Justin (Halliburton Energy Services) | Burleson, John (Halliburton Energy Services) | Azari, Mehdi (Halliburton Energy Services)
This paper was prepared for presentation at the 1999 SPE Latin American and Caribbean Petroleum Engineering Conference held in Caracas, Venezuela, 21–23April 1999.
- North America > United States > Oklahoma (0.46)
- North America > United States > Texas (0.46)
- North America > United States > Louisiana (0.28)
- (2 more...)
- Europe > United Kingdom > North Sea > Southern North Sea > Southern Gas Basin > Sole Pit Basin > Block 43/26 > Ravenspurn South Field > Rotliegend Formation (0.99)
- Europe > United Kingdom > North Sea > Southern North Sea > Southern Gas Basin > Sole Pit Basin > Block 43/26a > Ravenspurn Field (0.99)
- Europe > United Kingdom > North Sea > Southern North Sea > Southern Gas Basin > Sole Pit Basin > Block 42/30 > Ravenspurn South Field > Rotliegend Formation (0.99)
- Europe > United Kingdom > North Sea > Southern North Sea > Southern Gas Basin > Sole Pit Basin > Block 42/29 > Ravenspurn South Field > Rotliegend Formation (0.99)
Abstract Hydraulic fracturing is the preferred method for enhancing production rates and hydrocarbon recovery, as well as for maximizing the productivity of conventional and unconventional reservoirs. To optimize the effectiveness of the treatment and maintain wellbore integrity, the stimulation process should be designed and executed with both the wellbore configuration and target formations in mind. For wells in which multiple fractures are required, stimulations are normally performed sequentially, from the bottom layer to the top layer; however, open perforations above the target zone (whether fractured or not) can present significant challenges during the stimulation process. For these cases, the preferable solution has been to isolate the perforations using the cement-squeeze technique, but this process is not completely effective because of short penetration. The fragility of the cement slurry under typical stress cycles associated with the fracturing process or the complexity of the process could compromise the existing perforation integrity and the effectiveness of fracturing the lower zone. Alternatively, the well can be recompleted to isolate the zone mechanically, though this involves a rig operation, which, in zoned areas, is not cost-effective. One effective method to isolate existing perforations and help ensure deeper penetration of the isolation system without pulling out of the completion is squeezing a resin-based system with sufficient plasticity to maintain the isolation integrity under normal stress cycles. This paper documents the first application of resin blends to isolate existing perforations for the fracture stimulation of deeper prospective horizons. This isolation and stimulation process follows these steps: (1) the resin blend is squeezed into the wellbore using coiled tubing (CT); (2) the remaining resin blend is cleaned up using CT and a pressure test is performed; (3) the deeper horizon is perforated; (4) a minifrac and temperature survey are performed to evaluate existing perforation isolation; and (5) the fracture stimulation and production evaluation are performed.
- Europe > Middle East (0.40)
- Asia > Middle East (0.40)
- Africa > Middle East (0.40)
- North America > United States (0.29)