Browsing by Author "Malnar, Matija"

Now showing 1 - 2 of 2

Access status: Open Access ,
Contribution in testing swelling packers behavior
(2009) Matanović, Davorin; Simon, Katarina; Gaurina-Medimurec, Nediljka; Pašić, Borivoje; Malnar, Matija
Effect of polymer swelling that was considered to be a problem, gives today a possibility, to complete wells that are a problem one for conventional packer setting and sealing. Polymers (rubbers) can swell in hydrocarbons or water based fluids as well. Several ways of application have been accepted. Mainly they are connected with open hole and sand screen completions in unconsolidated formations. The ability of changing the volume to more than several hundred percent, can help to avoid packer failure. When defining swelling packer elements it is important to determine their mechanical properties, swelling speed in various fluids, and stability (ageing tests). To implement home made products it was necessary to provide laboratory testing equipment for such purpose. The developed apparatus enables use of different fluids, temperature change up to known reservoir temperature, and pressure differential that element can withstand.
Access status: Open Access ,
Frac-Pack well stimulation
(2010) Moslavac, Bojan; Pašić, Borivoje; Malnar, Matija
During the hydrocarbon production, the formation sand movement has a frequent negative influx to the process because of its hazardous nature. Gravel pack placement is a common well treatment procedure for prevention of formation sand flow to the wellbore. This method is used in petroleum engineering industrial practice since 1950s. Based on it as a conventional technique Frac-Pack method came up as a new modern technology of sand control containing gravel pack placement and hydraulic fracturing all-in-one procedure. In Frac-Pack application, the appropriate viscosified fluid and proppant selection has a key role for achievement of desired fracture height, length and width. Fracture dimensions are controlled by TSO (Tip-Screenout) fracturing procedure. In this paper basic types of proppant are presented as well as resin coated sand, which improves packing of fracture with proppant. Numerous and various Frac-Pack fluids able to resist the high temperature and pressure are described. Downhole Frac-Pack equipment is also presented. Paper also contains a field example of Frac-Pack application performed on one of the Adriatic offshore gas fields, Republic of Croatia.