SNI series jet pumps are designed to create stable and adjustable underbalance at the well bottomhole to induce flow during field-geophysical, hydrodynamic studies (Field geophysical surveys, hydrodynamic studies of wells) and physical impacts on bottomhole formation zone.
The distinctive feature is that the jet cartridge (nozzle + mixer) is mounted in the jet pump housing and run down the tubing.
Operating principle of the jet pump
The high pressure working fluid is pumped through the nozzle, creating a high velocity and at the point where the fluid exits the nozzle there is a pressure drop, resulting in suction of the fluid from the sub-packer zone. The fluids are then mixed in a mixer and brought to the wellhead.
The check valve prevents fluid from being absorbed into the formation when the working fluid stops pumping.
The sealing unit seals the geophysical cable (optical fiber, CT) both in static and in motion.
The use of jet pumps is currently the only way to instantly create, continuously maintain, smoothly control depression and induce inflow.
Solvable SNI Objectives:
- Research using geophysical cableat adjustable underbalances (with set underbalance value) in wells with static level up to 900-1200 meters. (at injection pressure of working fluid not less than 140 -160 atm, flow rate not less than 6 l/s) using geophysical cable, fiber optic cable, coiled tubing;
- Hydrodynamic Well Investigations;
- Impact on the bottomhole formation zone by physical stimulation (cyclic depression-repression method);
- Воздействие на пласт гидродинамическими и физическими методами в режимах депрессии;
- Cumulative perforation on the depression (on the cable);
- Removal of reaction products from the EPC after chemical and physical treatments;
- Cleaning of the bottomhole cavity from penetration products of drilling and cement muds.
Composition of SNI series pumps
Conditions of applicability of jet pump well investigation::
Pressure drop at the sealing unit of jet pump SNI-3 ΔPgu = ΔP+Pna+Pna(Hst) = ΔP+Pna(CH)+2Pna(Hst)
ΔR – depression on the reservoir;
Pna(Nst)** – pressure of pump unit spent on lifting of liquid static level;
Pna – working pressure of the pump unit when carrying out works with SNI-3 to record the inflow profile;
Rna(CH) – pump unit pressure spent on jet pump operation Rna(CH)=Rna-Rna(Nst);
The data in the tables are given to evaluate the possibility of geophysical cable movement through the sealing unit SNI-3 (taking into account 20 atm tubing injection pressure loss).
ΔРгу** = ΔР+Рна+Рна(Нст) < 240 атм
240 atm (over clamping the geophysical cable) when using the original SNI sealing assembly kit.
Composition of SNI-3:
- Jet pump housing (down tubes, jet cartridge, 2 check valve cartridges);
- Acid insert (removable insert that closes off the connection in the body to the tailpipe);
- KWD insert (retrievable insert with bypass valve for well development with adapter for self-contained pressure gauge);
- PIG insert (removable insert with a bypass valve mounted above the cable lug for recording downhole parameters with complex instruments, perforation, physical stimulation of the formation). Special version for registration of inflow profile with 900 m static at operation of SNI through tubing;
