Mitigating Water Production from High Viscosity Oil Wells in Unconsolidated Sandstone Formations

2021 ◽  
Author(s):  
Hamad AL-Rashidi ◽  
Mahmoud Reda Aly Hussein Hussein ◽  
Abdulaziz Erhamah ◽  
Satinder Malik ◽  
Abdulrahman AL-Hajri ◽  
...  
Keyword(s):  
Relative Permeability ◽  
Oil Recovery ◽  
Production Efficiency ◽  
Marked Change ◽  
High Viscosity ◽  
Water Production ◽  
High Permeability ◽  
Improved Oil Recovery ◽  
Lower Permeability ◽  
Water Cut

Abstract Large reserves of High-Viscous Oil in Kuwait calls for Improved Oil Recovery scenarios. In Kuwait unconsolidated sandstone formations, the sandstone intervals represent extensive reservoir intervals of sand separated by laterally extensive non-reservoir intervals that comprise finer-grained, argillaceous sands, silts and muds. The reservoir is shallow with high permeability (above 1000 mD) and under bottom aquifer pressure support. Due to strong viscosity contrast between oil and water, after breakthrough, the water cut rises quickly resulting in strong loss of production efficiency. Mitigating water production is thus mandatory to improve production conditions. The candidate wells have 2 to 3 open intervals in different rock facies with comingle production. The total perforated length is between 38 and 48 ft. Production is through PCP at a rate of around 300 bpd and BS&W is between 71 and 87%. The technology applied utilizes pre-gelled size-controlled product (SMG Microgels) having RPM properties, i.e. inducing a strong drop of relative permeability to water without affecting oil relative permeability. The size is chosen to selectively treat the high-permeability water producing zones while preserving the lower-permeability oil zones. The chemical can also withstand downhole harsh conditions such as salinity of around 170,000ppm and presence of 2% H2S. The treatment consisted of bullhead injection of 300 bbls of pre-gelled chemical through tubing. The first results seem very favourable, sincefor two wells, the water cut has dropped from 80 to 40% with almost same gross production rate. The incremental oil is more than 100 bopd. The third well did not show marked change after WSO treatment. The wells are under continuous monitoring to assess long-term performance. Such result, if confirmed, may lead to high possibilities for the improvement of heavy-oil reservoir production under aquifer support by mitigating water production with simple chemical bullhead injection.

scholarly journals Overview of Polymers for Improved Oil Recovery Treatments

2020 ◽  
Author(s):  
Mohamed Saeed Shamlooh1 ◽  
Ahmed Hamza ◽  
Ibnelwaleed Hussein ◽  
Mustafa Nasser ◽  
Saeed Salehi
Keyword(s):  
Oil Recovery ◽  
Oil And Gas ◽  
High Efficiency ◽  
High Water ◽  
High Permeability ◽  
Chemical Methods ◽  
Improved Oil Recovery ◽  
Profile Modification ◽  
Fractured Carbonate ◽  
Deep Profile

High water production in oil and gas wells reduces significantly the recovery factor. Mechanical as well as chemical methods are applied to shut off water productive zones. Crosslinked polymers showed high efficiency to seal off water zones in high permeability sandstone and fractured carbonate reservoirs. Moreover, emulsified polymeric formulations have been introduced for deep profile modification by changing the wettability of the rock and hence allowing selective plugging of water. This poster provides an overview of the polymeric formulations used for such application.

Design of in-Depth Conformance Gel Treatment to De-Risk ASP Flooding in a Major Carbonate Reservoir

2021 ◽  
Author(s):  
Mohammed T. Al-Murayri ◽  
Abrahim A. Hassan ◽  
Deema Alrukaibi ◽  
Amna Al-Qenae ◽  
Jimmy Nesbit ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Oil Recovery ◽  
Significant Risk ◽  
High Viscosity ◽  
Carbonate Reservoir ◽  
High Permeability ◽  
Laboratory Design ◽  
Gel Treatment ◽  
Viscosity Polymer ◽  
Chromium Acetate

Abstract Mature carbonate reservoirs under waterflood in Kuwait suffer from relatively low oil recovery due to poor sweep efficiency, both areal and microscopic. An Alkaline-Surfactant-Polymer (ASP) pilot 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. Design of the gel conformance treatment was multi-faceted. Rapid breakthrough of tracers at the pilot producer from each of the individual injectors, less than 3 days, implied a direct connection from the injectors to the producer and poses significant risk to the success of the pilot. A dynamic model of the SAMA pilot was used to estimate in the potential injection of either a high viscous polymer solution (~200 cp) or a gel conformance treatment to improve contact efficiency, diverting injected fluid into oil saturated reservoir matrix. High viscosity polymer injection scenarios were simulated in the extracted subsector model and showed little to no effect on diverting fluids from the high permeability streak into the matrix. Gel conformance treatment, however, provides benefit to the SAMA pilot with important limitations. Gel treatment diverts injected fluid from the high permeability zone into lower permeability, higher oil saturated reservoir. After a gel treatment, the ASP increases the oil cut from 3% to 75% while increasing the cumulative oil recovery by more than 50 MSTB oil over ASP following a high viscosity polymer slug alone. Laboratory design of the gel conformance system for the SAMA ASP pilot involved blending of two polymer types (AN 125SH, an ATBS type polymer, and P320 VLM and P330, synthetic copolymers) and two crosslinkers (chromium acetate and X1050, an organic crosslinker). Bulk testing with the polymer-crosslinker combinations indicated that SAMA reservoir brine resulted in not gel system that would work in the SAMA reservoir, resulting in the recommendation of using 2% KCl in treated water for gel formulation. AN 125 SH with S1050 produce good gels but with short gelation times and AS 125 SH with chromium acetate developed low gels consistency in both waters. P330 and P320 VLM gave good gels with slow gelation times with X1050 crosslinker in 2% KCl. Corefloods with the P330-X 1050 showed good injectivity and ultimately a reduction of permeability of about 200-fold. A P330-X 1050 was recommended for numerical simulation studies. Numerical simulator was calibrated by matching bulk gel viscosity increases and coreflood permeability changes. Numerical simulation indicated two of the four injection wells (SA-0557 and SA-0559) injection profile will change compared to water. Overall injection rate was reduced by the conformance treatment and was the corresponding oil rate. Total oil production from the center pilot production well (SA-0560) decreased with gel treatment but ultimately increased to greater rates

scholarly journals Carbon Storage and Enhanced Oil Recovery in Pennsylvanian Morrow Formation Clastic Reservoirs: Controls on Oil–Brine and Oil–CO2 Relative Permeability from Diagenetic Heterogeneity and Evolving Wettability

Energies ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3663
Author(s):  
Lindsey Rasmussen ◽  
Tianguang Fan ◽  
Alex Rinehart ◽  
Andrew Luhmann ◽  
William Ampomah ◽  
...  
Keyword(s):  
Carbon Storage ◽  
Enhanced Oil Recovery ◽  
Relative Permeability ◽  
Oil Recovery ◽  
Flow Behavior ◽  
Flow Unit ◽  
Water Production ◽  
Intergranular Porosity ◽  
Diagenetic Processes ◽  
Pore Types

The efficiency of carbon utilization and storage within the Pennsylvanian Morrow B sandstone, Farnsworth Unit, Texas, is dependent on three-phase oil, brine, and CO2 flow behavior, as well as spatial distributions of reservoir properties and wettability. We show that end member two-phase flow properties, with binary pairs of oil–brine and oil–CO2, are directly dependent on heterogeneity derived from diagenetic processes, and evolve progressively with exposure to CO2 and changing wettability. Morrow B sandstone lithofacies exhibit a range of diagenetic processes, which produce variations in pore types and structures, quantified at the core plug scale using X-ray micro computed tomography imaging and optical petrography. Permeability and porosity relationships in the reservoir permit the classification of sedimentologic and diagenetic heterogeneity into five distinct hydraulic flow units, with characteristic pore types including: macroporosity with little to no clay filling intergranular pores; microporous authigenic clay-dominated regions in which intergranular porosity is filled with clay; and carbonate–cement dominated regions with little intergranular porosity. Steady-state oil–brine and oil–CO2 co-injection experiments using reservoir-extracted oil and brine show that differences in relative permeability persist between flow unit core plugs with near-constant porosity, attributable to contrasts in and the spatial arrangement of diagenetic pore types. Core plugs “aged” by exposure to reservoir oil over time exhibit wettability closer to suspected in situ reservoir conditions, compared to “cleaned” core plugs. Together with contact angle measurements, these results suggest that reservoir wettability is transient and modified quickly by oil recovery and carbon storage operations. Reservoir simulation results for enhanced oil recovery, using a five-spot pattern and water-alternating-with-gas injection history at Farnsworth, compare models for cumulative oil and water production using both a single relative permeability determined from history matching, and flow unit-dependent relative permeability determined from experiments herein. Both match cumulative oil production of the field to a satisfactory degree but underestimate historical cumulative water production. Differences in modeled versus observed water production are interpreted in terms of evolving wettability, which we argue is due to the increasing presence of fast paths (flow pathways with connected higher permeability) as the reservoir becomes increasingly water-wet. The control of such fast-paths is thus critical for efficient carbon storage and sweep efficiency for CO2-enhanced oil recovery in heterogeneous reservoirs.

Key characteristics of three-phase oil relative permeability formulations for improved oil recovery predictions

1999 ◽  
Vol 5 (4) ◽  
pp. 339-346 ◽  
Author(s):  
E. F. Balbinski ◽  
T. P. Fishlock ◽  
S. G. Goodyear ◽  
P. I. R. Jones
Keyword(s):  
Relative Permeability ◽  
Oil Recovery ◽  
Improved Oil Recovery ◽  
Three Phase ◽  
Key Characteristics

scholarly journals A Novel Assisted Gas–Oil Countercurrent EOR Technique for Attic Oil in Fault-Block Reservoirs

Energies ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 402
Author(s):  
Kang Ma ◽  
Hanqiao Jiang ◽  
Junjian Li ◽  
Rongda Zhang ◽  
Kangqi Shen ◽  
...  
Keyword(s):  
Production Process ◽  
Oil Recovery ◽  
Production Efficiency ◽  
High Water ◽  
Gas Oil ◽  
Fault Block ◽  
High Water Cut Stage ◽  
High Water Cut ◽  
Gas Channeling ◽  
Water Cut

As the mature oil fields have stepped into the high water cut stage, the remaining oil is considered as potential reserves, especially the attic oil in the inclined fault-block reservoirs. A novel assisted gas–oil countercurrent technique utilizing gas oil countercurrent (GOC) and water flooding assistance (WFA) is proposed in this study to enhance the remaining oil recovery in sealed fault-block reservoirs. WFA is applied in our model to accelerate the countercurrent process and inhibit the gas channeling during the production process. Four comparative experiments are conducted to illustrate enhanced oil recovery (EOR) mechanisms and compare the production efficiency of assisted GOC under different assistance conditions. The results show that WFA has different functions at different stages of the development process. In the gas injection process, WFA forces the injected gas to migrate upward and shortens the shut-in time by approximately 50% and the production efficiency improves accordingly. Compared with the basic GOC process, the attic oil swept area is extended 60% at the same shut-in time condition and secondary gas cap forms under the influence of WFA. At the production stage, the WFA and secondary gas cap expansion form the bi-directional flooding. The bi-directional flooding also displaces the bypassed oil and replaced attic oil located below the production well, which cannot be swept by the gas cap expansion. WFA inhibits the gas channeling effectively and increases the sweep factor by 26.14% in the production stage. The oil production increases nearly nine times compared with the basic GOC production process. The proposed technique is significant for the development of attic oil in the mature oil field at the high water cut stage.

scholarly journals Effective Mechanisms to Relate Initial Rock Permeability to Outcome of Relative Permeability Modification

Energies ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4688 ◽  
Author(s):  
Faaiz Al-shajalee ◽  
Colin Wood ◽  
Quan Xie ◽  
Ali Saeedi
Keyword(s):  
Relative Permeability ◽  
Pore Radius ◽  
Water System ◽  
Water Production ◽  
High Permeability ◽  
Gas Reservoirs ◽  
Rock Permeability ◽  
Adsorbed Polymer ◽  
Permeability Modification ◽  
Initial Rock

Excessive water production is becoming common in many gas reservoirs. Polymers have been used as relative permeability modifiers (RPM) to selectively reduce water production with minimum effect on the hydrocarbon phase. This manuscript reports the results of an experimental study where we examined the effect of initial rock permeability on the outcome of an RPM treatment for a gas/water system. The results show that in high-permeability rocks, the treatment may have no significant effect on either the water and gas relative permeabilities. In a moderate-permeability case, the treatment was found to reduce water relative permeability significantly but improve gas relative permeability, while in low-permeability rocks, it resulted in greater reduction in gas relative permeability than that of water. This research reveals that, in an RPM treatment, more important than thickness of the adsorbed polymer layer ( e ) is the ratio of this thickness on rock pore radius ( e r ).

The Characteristics and Impacts Factors of Relative Permeability Curves in High Temperature and Low-Permeability Limestone Reservoirs

2014 ◽  
Vol 1010-1012 ◽  
pp. 1676-1683 ◽  
Author(s):  
Bin Li ◽  
Wan Fen Pu ◽  
Ke Xing Li ◽  
Hu Jia ◽  
Ke Yu Wang ◽  
...  
Keyword(s):  
Relative Permeability ◽  
Oil Recovery ◽  
Water Saturation ◽  
Phase Region ◽  
Two Phase ◽  
Experimental Conditions ◽  
Irreducible Water Saturation ◽  
Productive Water ◽  
Relative Permeability Curves ◽  
Water Cut

To improve the understanding of the influence of effective permeability, reservoir temperature and oil-water viscosity on relative permeability and oil recovery factor, core displacement experiments had been performed under several experimental conditions. Core samples used in every test were natural cores that came from Halfaya oilfield while formation fluids were simulated oil and water prepared based on analyze data of actual oil and productive water. Results from the experiments indicated that the shape of relative permeability curves, irreducible water saturation, residual oil saturation, width of two-phase region and position of isotonic point were all affected by these factors. Besides, oil recovery and water cut were also related closely to permeability, temperature and viscosity ratio.

Study on Performance Evaluation of Dispersed Particle Gel for Improved Oil Recovery

2013 ◽  
Vol 135 (4) ◽  
Author(s):  
Qing You ◽  
Caili Dai ◽  
Yongchun Tang ◽  
Ping Guan ◽  
Guang Zhao ◽  
...  
Keyword(s):  
Relative Permeability ◽  
Oil Recovery ◽  
Injection Pressure ◽  
Water Flooding ◽  
Improved Oil Recovery ◽  
Hydrocarbon Recovery ◽  
Heterogeneous Reservoirs ◽  
Atomic Force ◽  
Segregated Flow ◽  
Oil Flow

This work investigates the performance of dispersed particle gel (DPG) by core flow tests including injectivity, selective plugging, thermal stability, and improved oil recovery (IOR). Results showed that the resistance factor is small when DPG was injected, but obviously became larger while turning into brine water flooding. Both the oil and water relative permeability were reduced and greater reduction appeared in water relative permeability. DPG could block water flow without affecting oil flow, and oil–water segregated flow mechanism was proposed to explain this selective plugging. The injection pressure increases, caused by strong plugging due to the DPG aggregation aging in high temperature, which was consistent with the observation of atomic force microscope (AFM) photos. The DPG could effectively block high permeability zone and produce oil from low permeability zone, which could provide a practical way to enhance hydrocarbon recovery while reducing water production for extremely heterogeneous reservoirs.

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