A prediction formula for ratio of injection–production control area in triangle well pattern

Self Cite

Proper well placement should match the heterogeneity of reservoir and development schedule, in which case the displacement is balanced. A balanced displacement process can achieve a good development performance of reservoir. Present parameters to evaluate the displacement balanced degree are not fit for high water-cut oilfields and need a specific reservoir simulator. In this work, a well placement optimization method for offshore oilfield is established. A displacement balanced degree evaluation method is proposed based on Theil index. By using minimum Theil index as the objective function, well placement optimization model for offshore oilfield is built. In this model, constraints about the available infilling scope and minimum inter-well distance are considered to find the realizable optimal location. This optimization model is solved by a derivative-free optimization algorithm, differential evolution algorithm. This method is applied and validated in a semisynthetic offshore oilfield to find optimal well locations. Results demonstrate that this proposed method can find the optimal well placement for offshore oilfield to achieve a more balanced displacement and a higher oil recovery.

Section: Displacement Balanced Degree Evaluation Based On Theil Indexmentioning

confidence: 99%

Well placement optimization for offshore oilfield based on Theil index and differential evolution algorithm

Chen

Feng

Zhang

et al. 2017

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“…Unwanted water production is one of the major drawbacks occurring during extracting oil from fractured reservoirs (Wang and Seright 2006;Yu et al 2017). In most cases, it increases by increasing extracted hydrocarbons from oil reservoirs (Chen et al 2018;Izadmehr et al 2018). The pressure of the reservoir reduces proportional to the produced volume of excess water.…”

Section: Introductionmentioning

confidence: 99%

Oil recovery from fractured reservoirs using in situ and preformed particle gels in micromodel structures

Heidari

Ahmadi

Esmaeilzadeh

et al. 2019

Oil extraction often accompanied with relatively large amounts of water production causes several environmental and mechanical problems, particularly in oil-fractured reservoirs. One way to alleviate this problem is to use gels as a blockage agent. In this study, several micromodels with different geometries of fractures including a simple fracture, step fracture, fracture with variable mouth and fracture with a tiny crack were prepared. The amount of oil recovery was measured from these micromodels in the presence or absence of gel. In situ and preformed particle gels (PPGs) were injected into the micromodels to compare their ability in blocking fractures and increasing oil recovery. The BaCl 2 ·2H 2 O salt solution was used to swell PPGs. The amount of salt concentration was optimized so that PPGs had maximum ability to block fractures. Several PPG concentrations, 1000, 2000, and 3000 ppm, were examined to optimize the amount of PPGs, which have to be injected into the micromodels. Injection flow rate was optimized so that salt water could efficiently sweep the matrix structure. Results showed that both PPG and in situ gels have a considerable effect on decreasing water production and increasing oil extraction. However, PPGs were superior in comparison to in situ gels to increase oil recovery. It was found that increasing salt concentration decreases the swelling percentage of PPGs. The optimum amount of injection flow rate was found to be 0.1 mL/hr for all the prepared micromodels. The optimum concentration of PPGs was different for each micromodel.Publisher's Note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

“…Hitherto, several carbonate fractured reservoirs were examined and their fluid properties which influence oil recovery were determined (Abdelazim 2016;Barros-Galvis et al 2017;Parker-Lamptey et al 2017;Rahimi et al 2017;Ruidiaz et al 2017). However, controlling unwanted water production has been the major purpose of oil and gas producers (Chen et al 2017;Izadmehr et al 2017). One of the best cost-effective methods to alleviate this problem is gel treatment in which the major role of gel is to absorb water through highly permeable zones.…”

Section: Introductionmentioning

confidence: 99%

Synthesis of an efficient copolymer of acrylamide and acrylic acid and determination of its swelling behavior

Heidari

Esmaeilzadeh

Mowla

et al. 2018

The main purpose of this work is to prepare an efficient series of preformed particle gels (PPGs) and to study their behaviors to control unwanted water in oil fields. To this end, 12 copolymer samples composed of acrylamide and acrylic acid [poly(AAm-co-AA)] with different AAm/AA mole ratios and various mole percentages of N,N′-methylenebisacrylamide (MBA) were synthesized by a free radical copolymerization method. The gelation time of each sample was measured. The samples were dried in three consecutive steps: drying at atmospheric condition, drying in the oven, and drying in the vacuum oven, respectively. The chemical structure and morphology of the prepared PPGs were studied by a Fourier transform infrared spectroscopy and a scanning electron microscopy, respectively. Additionally, the swelling percentage of PPG samples was examined in different types of salt water (MgCl 2 ·6H 2 O, CaCl 2 ·2H 2 O, BaCl 2 ·2H 2 O, NaCl, KCl, and LiCl) with 200,000 ppm concentration and pH in the range of 3-8. Our results showed that the synthesized PPGs had swelling percentage (S%) in the range of 2-1300% for different types of salt solution. Moreover, the results confirmed that the swelling amount of PPG samples has a parabolic behavior against mole ratio of AAm/AA and decreases with increasing mole percentage of MBA.