Abstract: A cannula assembly comprises a cannula including a first portion, and a second portion extending from a distal end of the first portion, the second portion being more flexible than the first portion and configured to be inserted into a fistula vein of a patient. A needle is removably disposed in the cannula and configured to be displaced axially within the cannula.

Abstract: A method for processing heavy crude oils comprising a) atmospheric distillation of a heavy crude oil having a high content of metals, asphaltenes and sulfur; b) solvent extraction of the atmospheric distillation residue to obtain an extract with characteristics equivalent to those which an atmospheric residue derived from light crude oil and a raffinate fraction, solid at ambient conditions, in which are concentrated the asphaltenes, metals and sulfur present in the original crude oil; c) vacuum distillation of the deasphalted extract, obtaining a light fraction or gas oils with characteristics adequate to be subjected to a secondary conversion process, plus a bottoms fraction or vacuum residue; d) treatment of the vacuum gas oils in a conversion stage and e) subjecting the bottoms of raffinate from the extraction stage to a metallurgical process, in admixture with cokeable coal and coke fines to production of metallurgical coke.