Basic Study On The Application Of Bubble Drain And Anti-polymerizing Agent In Gas Well

In the process of gas well production,bottom hole effusion and wellbore hydrate blockage are the technical problems faced by the safe and efficient production of gas wells,and have become the bottleneck problem restricting the production of gas wells.The use of bubble drain agent and hydrate anti-polymerization agent is a good means to solve the problem of bottom-hole effusion and hydrate blockage,respectively.At present,the use of bubble drain agent and hydrate anti-polymerization agent is an important means to solve the bottom-hole effusion effusion and hydrate.However,there are some defects such as poor stability and small liquid carrying capacity.Based on the principle that the foaming agent and the hydrate anti-polymerization agent have similar surfactant structure,the surfactant and its compound system are selected in this paper,and its foaming and hydrate anti-polymerization properties are evaluated.Combined with theoretical analysis,the surfactant compound system with both bubble discharge and hydrate anti-polymerization function is obtained.The main conclusions of this paper are as follows:(1)The surfactant cetyl trimethyl ammonium chloride(CTAC),coconut oil amide propyl betaine(CAB)and other surfactants were mixed to obtain the foam-antipolymerization integrated agent(TCJ)binary system,the formula:0.05%CTAC+0.7%CAB.At room temperature,there is no settlement and stratification after 24h of TCJ system,which indicates that the stability of the system is good.The initial foam volume of the formulation is 415 m L and the half-life time is 5.5 min by using a high-speed agitator.The initial foam height of TCJ system measured by Roche foam instrument at 50?is 14.6 cm,and after 25 min,the foam height remains at 10.5 cm,indicating that the system has a good temperature resistance.When the temperature of TCJ system is 65?,the liquid carrying capacity is 125 m L,and the liquid carrying rate is 62.5%.At 15%methanol addition,the initial foam height can still reach 12.8cm.When the Na Cl addition is 12.5%,the initial foam volume can reach 410 m L,and the half-life time is 6.9 min.TCJ system has good compatibility with poly vinyl pyrrolidone(PVP)and can prolong half-life time.Using self-assembled micro-morphology observation device to observe hydrate,the hydrate formed by 20%tetra hydro furan(THF)in the TCJ system was found to be very loose and small.Through measuring and comparing the DSC curve of 20%THF before and after adding TCJ system,it can be found that the phase transition point of the hydrate decreases from 4.32?to 2.12?after the addition of the polymer inhibitor,and the decrease of the phase transition point indicates that the integrated agent has the characteristics of thermodynamic inhibitor.Hydrate formation can be inhibited to a certain extent.(2)The surfactant cetyl trimethyl ammonium chloride(CTAC),dodecyl dimethyl betaine(BS-12),fatty alcohol polyoxyethylene ether sodium sulfate(AES)and other surfactants were mixed to obtain the ternary system of foam-antipolymerization integrated agent(TSE),and the formula was 0.05%CTAC+0.9%BS-12+0.4%AES.At room temperature,there is no settlement and stratification after 24h of TSE system,which indicates that the stability of the system is good.The initial foam volume of the formulation is 565 m L and the half-life time is7.8 min by using a high-speed agitator.The initial foam height of TSE system measured by Roche foam instrument at 50?is 21.5 cm.When the temperature of TSE system is 65?,the liquid carrying capacity is 155 m L,and the liquid carrying rate is 77.5%.At 15%methanol,the initial foam height can still reach 17.5 cm.When the Na Cl,Ca Cl₂addition is 12.5%,the initial foam volume reaches 560 m L,565 m L,respectively.TSE system has good compatibility with poly vinyl pyrrolidone(PVP)and can prolong half-life time.The hydrate formed by 20%tetra hydro furan(THF)in the TSE system is obviously loose and the amount of hydrate is small,which indicates that the integrated agent can inhibit the accumulation and formation of hydrate.Through measuring and comparing the DSC curve of 20%THF before and after adding TSE,it can be found that the phase the phase transition point of the hydrate decreases from 4.32?to 1.35?after the addition of the polymer inhibitor,and the decrease of the phase transition point indicates that the integrated agent has the characteristics of thermodynamic inhibitor and can inhibit the formation of hydrate to a certain extent.The foam performance and anti-polymerization effect of ternary TSE system are better than that of binary TCJ system.(3)The surfactant cetyl trimethyl ammonium chloride(CTAC),alkylphenol polyoxyethylene ether(OP-10),sodium dodecyl sulfate(SDS)and other surfactants were compounded to obtain a ternary system of foam-antipolymerization integrated agent(TPS)with a formula of 0.05%CTAC+0.5%OP-10+0.02%SDS.At room temperature,there is no settlement and stratification after 24h of TPS system,which indicates that the stability of the system is good.The initial foam volume of the formulation is 540 m L and the half-life time is7.5 min by using a high-speed agitator.The initial foam height of TPS system measured by Roche foam instrument at 70?is 17.4 cm,indicating that the system has a good temperature resistance.When the temperature of TPS system is 65?,the liquid carrying capacity is 145m L,and the liquid carrying rate is 72.5%.At 15%methanol addition,the initial foam height can still reach 13.8 cm.TPS system has good compatibility with poly vinyl pyrrolidone(PVP)and can prolong half-life time.The hydrate formed by 20%tetra hydro furan(THF)in the TPS system is obviously loose and the amount of hydrate is small,which indicates that the integrated agent can inhibit the accumulation and formation of hydrate.Through measuring and comparing the DSC curve of 20%THF before and after adding the TPS system,it can be found that the phase transition point of the hydrate decreases from 4.32?to 0.92?,and the decrease of the phase transition point indicates that the integrated agent has the characteristics of thermodynamic inhibitor.Hydrate formation can be inhibited to some extent.To sum up,it can be concluded that the foam performance of the TSE system is the best,the foam performance of the TPS system is slightly poor,but the anti-polymerization effect of the system is the best.Considering the economic cost,the TPS formula is suitable for field application.As a result,the TPS system is suitable for field application test.