| The Qingshui subsag area of the Western Depression of Liaohe basin is the largest oil generating basin in Liaohe basin.A tight sandstone reservoir with considerable potential for development is found around the Qingshui sag.The estimated oil reserves are 4.7 billion tons and the natural gas reserves are 190 billion cubic meters.Such low permeability reservoirs are buried deep,low porosity,small throat,poor fluid permeability and low productivity.Usually,fracturing is needed to achieve industrial airflow.In the early stage,the fractured reservoir was constructed in the tight sandstone reservoir surrounding the clean water depression,but no good results were achieved.The volume fracturing for the transformation of ideas,have a general understanding of the surrounding water in tight sandstone gas reservoirs,the volume fracturing transformation of the concept of dense sand layer to carry out the "high strength sand" and "fine layering" and "slot plugging","jet drilling holes to" naked eye "fracturing packer multi-stage fracturing string" technology research and implementation,according to the characteristics of dense sandstone reservoirs,based on laboratory experiment selected a carboxymethyl hydroxypropyl guar gum fracturing fluid system,and to evaluate the performance of the fracturing fluid system,pressure to ensure that the supporting agent does not return to the situation next,should as soon as possible to return the fracturing fluid discharge formation,reduce formation damage.Through the systematic and meticulous research of fracturing technology for tight sandstone reservoirs,a targeted fracturing technology for tight sandstone reservoirs has been formed,which provides solid technical support for the exploration of tight sandstone reservoirs in Liaohe Oilfield. |
