Long-term Sand Control String Design In Steam Huff And Puff Wells And Relative Technology Researches

Shengli oil filed has both abundant heavy oil reservoirs and production which hasalready become an important succeeding production target for the stability of Shengli oilfield’s production. Nowadays, steam huff and puff is the main developing treatment forShengli heavy oil reservoirs, and conventional sand control are the most frequently-used butcan hardly fulfill the developing needs of once sand contrl multicycle steam huff and puff.Therefore sand control barrier stability of multicycle steam huff and puff wells is researchedsystematically and thoroughly which provides a guiding significance to the solving ofproblems facing in the steam huff and puff.First, reusable gravel packing sand control docking tool structure design is completed.Tool setting assemblies parameters, slips hoisting capacity, inner central tube strength,hydraulic cylinder strength parameters, unsetting assemblies and setting pin parameters arechecked and calculated as key issues. Modified fluorine rubber materials are selected as thehigh temperature seals of the long-term sand control string, on which basis, string indoorperformance tests and string comprehensive performance tests are carried out. The researchshows that every assemblies of the long-term sand control string are flexible and reliable,which performance meets the standard of acid, alkali and salt resistant. The tool developed inthe paper can perfectly fulfill the need of high pressure gravel packing and followed-up sandsupplement.Second, elastic modulus and yield strength temperature-effect equations of four steelgrades of pipe materials are fitting established. Sand control string base pipestrength-decreasing model with hole perforated is established draw lessons from casingstrength-decreasing model with hole perforated. Besides, sand control string thermal stabilityanalysis equation is established by uniting equations of thermal stress and temperature field.On the previous basis and FEPG system, sand control string thermal stability simulation finite element program is developed and the impacts in several conditions on thermal stability areanalized. The research shows that perforated hole density, hole diameter and outter diameterare the main factors which impact the decrease of central pipe strength. P110grade steel isrecommaned as base pipe material. Gravel pack may increase the thermal stability of sandcontrol string. Last, the thermal strength is weak at the junction of adequate packing areas andinadequate packing areas; compensator can significantly improve the thermal stability ofstrings. Compensation distance in different temperature of steam injection and different lengthof string pipe is given.Again, high temperature multilayer coated proppant which has three coating material aspreconsolidation resin, consolidation resin, inert layer is developed. Coating layermaterialformulations, coating treatment and preparation process are also researched and on this basis,wet heating treatment evaluation experiment syetem is established. Wet heating evaluationstandard is raised and the evaluation of developed coated proppant in the paper is completed.The research shows that, the proppant developed in the paper has consolidation strength morethan7MPa in wet heating condition with a broken rate of2.4%. The proppant consolidationstrength after4round simulated steam huff and puff is till more than7MPa, which shows agreat capability to producing need.Finally, calculation model of critical flow rate in perforated hole is selected in watercarrier and viscous carrier conditions, minimum multislug gravel packing sand carrierpumping rate calculation model is established, and the combination of multislug is optimized.Field test has been carried out in Well GDN5-604which shows a result of1.17t/d daily oilproduction increase compare to other wells in the same block, which demonstrated a greatsuccess in oil production and sand control.Important factors which affect the sand control barrier stability of multi steam huff andpuff wells are systemically researched in this paper. The results may provide important theoryand application value to the high efficient development of this kind of reservoir.