Typically, horizontally fractured wells use either gas lift or ESPs in the beginning if the well needs help getting the water out of the well. This lift helps the liquid get from the bottom of the well to the top either by making the liquid not as heavy (gas lift, soap sticks), by pushing it up the well from the bottom (beam/rod pumps, electronic submersible pumps, plunger lift), or by sucking it up the well from the top (wellhead compression, velocity strings). The help is in the form of “artificial lift” (as opposed to the well flowing liquid to the surface by itself). Sometimes the reservoir just doesn’t have enough pressure to push the water up, and we need to give it some help. When water is pushed down hole, the reservoir then has to push it back up before the oil or gas can follow behind it. A gallon of fresh water weighs about 8.3 lbs, while a gallon of gasoline weighs only 6 lbs (and a gallon natural gas is a mere fraction of that). Water is heavier than oil and gas, something we’ve all seen when the salad dressing separates with the oil on top. The bottom line is a LOT of water is pumped down into the reservoir in order to fracture a reservoir, typically 2-8 million gallons of water per well. To transport the sand into the fractures, the sand is suspended in water and pumped down the pipe in a massive operation. These fractures are created by pumping really hard against the reservoir rock with water (“hydraulic”), making a break (“fracture”) in the rock, then filling that fracture with sand to keep it open (“propped”). 99% of wells drilled in the US today are horizontally drilled unconventional wells with a bunch of man-made propped hydraulic fractures.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |