Current global energy demand and supply gap needs the best engineering methods to recover hydrocarbonsfrom the unconventional hydrocarbon resources. Unconventional resources mostly found in highly stressed,over pressured, and deep formations, where the rock strength and integrity both are very high. The pressureat which the rock fractures or simply the breakdown pressure is directly correlated with the rock tensilestrength and the stresses acting on them from the surrounding formations. When fracturing these kindsof rocks, the hydraulic fracturing operation becomes much more challenging and difficult, and in somescenarios reached to the maximum pumping capacity limits. This reduces the operational gap to optimallyplaced hydraulic fractures. In the present research study, a novel thermochemical fracturing approach is presented to reduce thebreakdown pressure of the high-strength layered formations. The new approach not only reduces thebreakdown pressure of the layered rocks but also generate highly conductive fractures which can penetratein most of the layers being subjected to fracturing. The hydraulic fracturing experiments presented in thisstudy are carried out on four layered cement block samples. The composition of cement blocks is synthesizedin this way that it simulates the real rocks. The results showed that the newly proposed thermochemical fracturing approach reduced the breakdownpressure in layered rocks from 1495 psia (reference breakdown pressure recorded from conventionalhydraulic fracturing technique) to 1107 psia. The post treatment experimental analysis showed thatthe thermochemical fracturing approach resulted in deep and long fractures, passing through majorityof the layers while conventional hydraulic fracturing resulted in a thin fracture affected only the toplayer. Thermochemical fluids injection caused the creation of microfractures, improved the porosity andpermeability, and reduces the Young's modulus of the rocks. The new technique is cost effective, non-toxic,and sustainable in terms of no environmental hazards.
|Original language||English (US)|
|Title of host publication||Society of Petroleum Engineers - SPE/PAPG Pakistan Section Annual Technical Symposium and Exhibition 2019, PATS 2019|
|Publisher||Society of Petroleum Engineers|
|State||Published - Jan 1 2019|