Experimental study of polyacrylamide gel in close‐in well operation

Abstract

An optimized polymer gel, known as temporary gel, based on polyacrylamide sulfonated copolymer, and a chromium acetate hydroxide were synthesized to close‐in the wells during applying well servicing work. Based on bottle tests, polymer gel with 28 000 ppm of polymer concentration, and 0.105 ratio of crosslinker to polymer, was selected. The pressure effect within the range of 1000 to 4000 psi indicated not impressive effect of pressure on the gel properties. As the results of creep test clarified, yield strength of the gel was measured at temperature of 90°C, and 2000 Pa. Moreover, the results of an experiment under simulated well condition showed a linear correlation between the height of polymer gel column, and the strength and persistence of gel against fluid pressure. At last, process of degelling with 40 g of optimum gel was performed using 14 g of 30 wt% solution of citric acid during 4 hours.

Chemical sand production control: a review of materials, methods and characterization

“…Hajipour et al used polyacrylamide to synthesize a temporary plugging gel. The polymer can undergo a normal gelation reaction when the pressure ranges from 6.9 to 27.61 MPa (Hajipour et al, 2018). The Young's modulus of the generated gel is 190.3 MPa with a strong network structure.…”

A Review on Chemical Sand Production Control Techniques in Oil Reservoirs

“… The creep test involves the polymer network’s strength and degree of flexibility by studying the deformation of the polymer, in terms of stress. In this experiment, constant stress in which the strain changes with time is called the yield stress Therefore, rheological tests can be used to predict the performance of polymers under the reservoir conditions in controlling sand production.…”

“…The creep test involves the polymer network’s strength and degree of flexibility by studying the deformation of the polymer, in terms of stress. In this experiment, constant stress in which the strain changes with time is called the yield stress …”

“…In this experiment, constant stress in which the strain changes with time is called the yield stress. 206 Therefore, rheological tests can be used to predict the performance of polymers under the reservoir conditions in controlling sand production. Moreover, these tests indicate the importance of rheology in ensuring the success of polymers in sand control.…”