Abstract: A liquid phase enhanced oil recovery system that, in a stimulation phase, pumps a liquid mixture of propane (C3) and butane (C4) having a starting ratio of C3 to C4 into a well. During a subsequent production phase, liquid C3 and liquid C4 is recovered by a stabilizer from the produced oil, and, in addition, C3 and C4 can be recovered from the produced hydrocarbon vapor and liquefied, The ratio of liquid C3 to liquid C4 can then be re-adjusted and may not be the same as the starting ratio. All of the liquid C3-C4 can be recycled back into the well in subsequent stimulation phases. The method works at relatively low pressures, so that a pump or pumps can be used for stimulation treatment. The site equipment is compact enough that it can be mounted on one or more skids to ensure transportability to be used on other wells.

Abstract: A liquid phase huff and puff method of enhanced oil recovery (EOR) applied to multiple groups of existing horizontal or vertical wells in a shale or tight rock reservoir resulting in additional oil recovery. The method utilizes a pumping phase for a chosen pumped well group, and a production phases for the remaining well groups. The production phases typically last longer than the pumping phases. The method operates such that while one of the well groups is pumping, the remaining well groups are producing, A new pumped well group is chosen from the production well groups upon completion of each pumping phase, with the previous pumped well group being converted to a producing well group.

Abstract: A liquid phase enhanced oil recovery system that, in a stimulation phase, pumps a liquid mixture of propane (C3) and butane (C4) having a starting ratio of C3 to C4 into a well. During a subsequent production phase, liquid C3 and liquid C4 is recovered by a stabilizer from the produced oil, and, in addition, C3 and C4 can be recovered from the produced hydrocarbon vapor and liquefied, The ratio of liquid C3 to liquid C4 can then be re-adjusted and may not be the same as the starting ratio. All of the liquid C3-C4 can be recycled back into the well in subsequent stimulation phases. The method works at relatively low pressures, so that a pump or pumps can be used for stimulation treatment. The site equipment is compact enough that it can be mounted on one or more skids to ensure transportability to be used on other wells.

Abstract: A liquid phase enhanced oil recovery system (EOR) that pumps a liquid mixture consisting mostly of propane (C3) and butane (C4) into a horizontal or vertical well during the stimulation treatment phase to recover additional hydrocarbons from the reservoir. During the subsequent production phase a liquid mixture is produced that includes water, hydrocarbon vapor, and hydrocarbon liquids which include oil and C3 and C4. The C3 and C4 is recovered from the hydrocarbon vapor and can be liquefied, combined with the liquid C3-C4 recovered from the produced liquid hydrocarbon stream and then all the C3-C4 can be recycled back into subsequent stimulation treatment phases. The method works at relatively low pressures so that a pump can be used for stimulation treatment. The site equipment is light enough that it can be mounted on one or more skids to ensure transportability to be used on other wells.