In today's challenging world of exploration, Hydro Fracturing (HF) is an important tool in the oilfield arsenal that enables operators to understand the formation potential deliverability. More and more companies today are adopting hydrofracturing as part of the exploration strategy for better quantification of hydrocarbon production. GSPC decided to precisely do this in their Tarapur asset due to very low rates of production post drilling phase.GSPC has drilled quite a few wells in the Tarapur field which is located near the Ahmedabad city. In order to verify the ultimate producability of these formations, hydraulic fracturing is the most suitable strategy. 6 wells, which showed presence of oil, were chosen as the stimulation candidates for the production enhancement and production potential identification from this field. This project primarily focused on the exploration and development of the Kalol Sand of the Tarapur field.The entire HF operation consisted of two parts known as the Datafrac and the Main Fracturing Treatment. Datafrac was done to estimate critical formation and fluid parameters such as like fracture closure pressure, Fluid Efficiency and Leakoff Coefficients which all are determined to design the most optimum job for maximizing ultimate recovery. Reservoir transmissibility validation was also performed via the injection test that is done as a part of the Datafrac injection test. This paper discusses the planning and design processes leading to the successful execution of the hydro frac treatments and the post-stimulation results. The experience and lessons learned during the stimulation treatment design, execution and poststimulation results will be discussed. Lessons learned from this successful experience are discussed as a way to enhance the benefits from this promising technology that will lead to more successful developments of the exploration wells in India.

Dholka, a small field situated in the Cambay basin of Gujarat consists of mainly oil producing horizons namely upper, lower, and middle pay. However, in a well D-A there is approximately 20 m interlaying shale above the upper pay showing a significant amount of C1 and C2 components evident from mud log showing yellow fluorescence. Around 24% of gas content was estimated, and hence, it was a considered as a potential source of gas pay that could be exploited using the hydraulic fracturing technique. This discovery occurred during the drilling and development phase for the lower, middle, and upper pay formations and is the first play in the field to have shale gas characteristics encountered. The change in cuttings and the show of gases in the chromatograph led to the careful collection of all the cuttings across these intervals, which were then sent for lithofacies and petrographic studies that confirmed that more than 50% of the facies are shale. Apart from the upper pay and lower pay, an interesting shale pay zone was encountered in the well D-A during drilling. The hydrocarbon flow potential post perforating was very low because the formation was extremely tight. Hydraulic fracturing was critical for the successful producibility of such wells. To assess the maximum potential of both hydrocarbon bearing intervals, it was decided to hydro-fracture both shale and typical oil bearing intervals separately. The planning and design processes of this project led to the successful execution of the hydraulic fracture. Encouraged by the results on the well D-A, another well D-B was similarly hydro-fractured as pilot test to explore shale gas in the area. Lessons learned from this successful experience have led Joshi Technologies to consider this source for further detailed exploration and development.

Fracturing in Talisa formation (thin layer, shallow, and less shaliness contrast) has met several challenges. Using conventional fracturing technique (to achieve a large conductivity, placing a large volume of proppant, high rate and high pressure), it has a risk of unexpected growing in height, breaking the upper and lower barriers, early screen out, sand flowback and end up with ineffective treatment. The more gentle fracturing treatment is introduced to this formation by using lower rate of injection, lower pressure, less aggressive proppant concentration, less damaging fluid and multiple cycle of injection stage. On conventional fracturing treatment , a large fracture geometry is usually expected at the end of treatment. Instead of creating a large fracture half length, this fracturing approach will create multiple fracture with different orientation which connect each other and lead an effective stimulation. The low injection rate during the treatment will also lead a shear dilatation mechanism on reservoir which will enhance the permeability. On this fracturing treatment, observation of the formation response is conducted at the beginning of the stage, during treatment, during decline in every stage and at the end of the stage to see how the injection in every stage can improve the formation. The objectives of this paper is to share the case study of technique implementation on Langgak Field, Rokkan Hulu Riau. This Field is operated by SPR Langgak and the fracturing treatment is provided by NESR. 3 wells are treated and showing good indication of fracturing result. This paper will give different perspective to the audience for a non-conventional fracturing practice, especially for Talisa formation, which could be also applied in other field which has similar characteristics.