Field Implementation of In-Depth Conformance Gel Treatment Prior to Starting an ASP Flooding Pilot

Abstract

Mature carbonate reservoirs under waterflood in Kuwait suffer from relatively low oil recovery due to poor volumetric sweep efficiency, both areal, vertically, and microscopically. An Alkaline-Surfactant-Polymer (ASP) pilot using a regular five-spot well pattern is in progress targeting the Sabriyah Mauddud (SAMA) reservoir in pursuit of reserves growth and production sustainability. SAMA suffers from reservoir heterogeneities mainly associated with permeability contrast which may be improved with a conformance treatment to de-risk pre-mature breakthrough of water and chemical EOR agents in preparation for subsequent ASP injection and to improve reservoir contact by the injected fluids. Each of the four injection wells in the SAMA ASP pilot was treated with a chemical conformance improvement formulation. A high viscosity polymer solution (HVPS) of 200 cP was injected prior to a gelant formulation consisting of P300 polymer and X1050 crosslinker. After a shut-in period, wells were then returned to water injection. Injection of high viscosity polymer solution (HVPS) at the four injection wells showed no increase in injection pressure and occurred higher than expected injection rates. Early breakthrough of polymer was observed at SA-0561 production well from three of the four injection wells. No appreciable change in oil cut was observed. HVPS did not improve volumetric sweep efficiency based on the injection and production data. Gel treatment to improve the volumetric conformance of the four injection wells resulted in all the injection wells showing increased of injection pressure from approximately 3000 psi to 3600 psi while injecting at a constant rate of approximately 2,000 bb/day/well. Injection profiles from each of the injection well ILTs showed increased injection into lower-capacity zones and decreased injection into high-capacity zones. Inter-well tracer testing showed delayed tracer breakthrough at the center SA-0561 production well from each of the four injection wells after gel placement. SA-0561 produced average daily produced temperature increased from approximately 40°C to over 50°C. SA-0561 oil cuts increased up to almost 12% from negligible oil sheen prior to gel treatments. Gel treatment improved volumetric sweep efficiency in the SAMA SAP pilot area.

Theoretical Justification of the Thermal Method – Steam Cyclic Treatment of Wells of the X Deposit

“…The presence of high-viscosity oil (HVO) deposits in Kazakhstan with large concentrations of associated elements has not contributed to the increase in production of this type of petroleum feedstock for a long time due to its high cost. Moreover, chemical compounds of high-viscosity oil have a negative impact on oil refining processes, reduce the performance of petroleum ДОБЫЧА products, and corrode equipment [6]. In this regard, reduction of the HVO cost necessitates the introduction of new innovative technologies and methods for its extraction.…”

Forecasting Orf by the Martos Method and the Statistical Method Using the Example of Deposit X

“…Wells №№14 and 29, after opening the salt strata with a thickness of 874 m and 1042 m, respectively, passed about 1000 m through Permian-Triassic terrigenous deposits. According to well logging data [5][6][7], sandstones are almost completely absent in the sub-canopy part of the interval and the prospects for discovering deposits here are very low. T-V).…”

“…Analysis of core studies. Basic information about the nature of illumination from core material and laboratory analyzes of the productive strata was obtained during exploratory drilling in 21 wells (№№1, 2, 3,5,6,7,10,11,13,14,19,20,21,22,23,24,25,36,37,38,40).…”

Study of the Dynamics of Associated Drill Strings Interacting With the Well Wall

“…Research. In one of the early works [5], the column is considered as a torsional pendulum with one degree of freedom, and the dependence of the moment of resistance to rotation at the bottom point on the angular velocity is considered to decrease exponentially. In [6], a theory of oscillations with periods of slipping and stagnation was constructed under the assumption of a jump-like characteristic of friction in the "bit-bottomhole" pair.…”

“…In this case, the cross-sectional area is F=40cm 2 . At E=2.1е 5 MPa, ρ=7.8е 3 kg/m 3 , the speed of propagation of longitudinal waves will be с=(Е/ρ) 1/2 =5000 m/sec, and the main period of longitudinal oscillations T=0.4s. The last two parameters (wave speed and oscillation period) appear when considering dynamic processes in the column.…”