Apparatus and method for withdrawing fluid from a source of fluid such as a pipeline

A method for continuously withdrawing a fluid from a fluid supply comprising:

• alternately withdrawing the fluid from the fluid supply to two separate containers;
• and whilst one container is being filled, mixing the fluid in the second container by withdrawing the fluid from said second container and passing the fluid through a mixer and then returning the fluid to said second container;
• sampling the mixed fluid;
• and
• withdrawing said fluid from said second container.

An oil pipeline apparatus for withdrawing oil from a pipeline, said apparatus comprising:

• withdrawal means connectable to the pipeline for withdrawing oil form the pipeline;
• first and second collection apparatus operable alternately to collect a proportion of the oil withdrawn from the pipeline;
• fluid mixing means connectable alternately to the two collection apparatus to mix the fluid collected in one of the collection apparatus whilst the other collection apparatus is collecting oil from the pipeline, said fluid mixing means including a pump means for withdrawing fluid from one of the collection apparatus and passing the withdrawn fluid through a mixer such that the withdrawn fluid is passed back to the one of the collection apparatus and passes through the one of the collection apparatus during mixing;
• means for sampling a predetermined quantity of the mixed oil;
• and
• means for returning the remainder of the mixed oil to the pipeline.

An apparatus for continuously withdrawing a fluid from a source of fluid, said apparatus comprising:

• two collection apparatus for alternately collecting some of the fluid, each collection apparatus including a vessel having a moveable wall and being connectable to the source of the fluid;
• fluid mixing means, alternately connectable to said two collection apparatus, for mixing the collected fluid in one of said two collection apparatus while the other collection apparatus is collecting fluid from the source of fluid, said fluid mixing means including a pump means for withdrawing fluid from one of the collection apparatus and passing the withdrawn fluid through a mixer such that the withdrawn fluid is passed back to the one of the collection apparatus and passes through the one of the collection apparatus during mixing;
• means for sampling a predetermined quantity of the mixed fluid;
• second pump means for pumping the mixed fluid out of one of the vessels;
• and
• connecting means, operatively connected between said second pump means and each of said vessels, for alternately connecting said second pump means to one of said vessels so that as fluid is pumped out of said one of said vessels, said movable wall of said one of said vessels is moved and fluid is withdrawn from said source of fluid into said one of said vessels.