Controlled Frac Height Growth Technique to Avoid Contacting Water-Bearing Layer

Many techniques have been used to model, diagnose and detect fracture dimension and propagation during hydraulic fracturing. Diagnosing fracture dimension growth vs time is of paramount importance to reach the desired geometry to maximize hydrocarbon production potential and prevent contacting undesired fluid zones. The study presented here describes a technique implemented to control vertical fracture growth in a tight sandstone formation being stimulated near a water zone. This gas well was completed vertically as openhole with Multi- Stage Fracturing (MSF). Pre-Fracturing diagnostic tests in combination with high-resolution temperature logs provided evidence of vertical fracture height growth downward toward water zone. Pre-fracturing flowback indicated water presence that was confirmed by lab test. Several actions were taken to mitigate fracture vertical growth during the placement of main treatment. An artificial barrier with proppant was placed in the lower zone of the reservoir before main fracturing execution. The rate and viscosity of fracturing fluids were also adjusted to control the net pressure aiming to enhance fracture length into the reservoir. The redesigned proppant fracturing job was placed into the formation as planned. Production results showed the effectiveness of the artificial lower barrier placed to prevent fracture vertical growth down into the water zone. Noise log consists of Sonic Noise Log (SNL) and High Precision Temperature (HPT) was performed. The log analysis indicated that two major fractures were initiated away from water-bearing zone with minimum water production. Additionally, in- situ minimum stress profile indicated no enough contrast between layers to help confine fracture into the targeted reservoir. Commercial gas production was achieved after applying this stimulation technique while keeping water production rate controlled within the desired range. The approach described in this paper to optimize gas production in tight formation with nearby water contact during hydraulic fracturing treatments has been applied with a significant improvement in well production. This will serve as reference for future intervention under same challenging completion conditions.

UNUSUAL ANKLE FRACTURE: A LITERATURE REVIEW

Background:- Fractures of the talus are unusual, and talar body fractures in the sagittal plane are still rarer. Its treatment aims a crucial anatomic reduction to reimpose congruency of the ankle and decrease the risk of avascular necrosis by conserving any remaining blood supply. We present the case of a body talar fracture in the sagittal plane related to fracture of the medial malleolus in an adult. The mechanism of the fracture was, internal rotation, plantar hyperexion, and axial compression. We performed an open reduction and stabilization with two screws for the talus and screwed the medial malleolus. Material & Methods:- We included 30 patients in this study among which a 25 years old man presented in Department Of Orthopaedics, Mgmmch, Jamsehedpur, Jharkhand with a grossly expand and deformed right ankle. Radiographs revealed a displaced vertical fracture of the neck of the talus traversing through the body with vertical fracture of the medial malleolus and medial talar shift. Results:- Fractures of the talus have a relatively little incidence accounting for 0.3% of all bone fractures and 3% to 6% of all foot fractures.[1,2] Union of the fracture in such a case is extremely slow as it depends on a new blood supply growing into the avascular bone.[3] Hence, the fracture needs preservation for a long time, and non-weight bearing is recommended for three months or until the union has occurred. Malunion can produce substantial alteration in load across the ankle and subtalar joints and result in arthrosis. The reported case should have the best prognosis as it was closed and underwent immediate operative reduction with early signs of revascularization. After 13 months following the injury, the patient had the best range of movement with some pain. Conclusion:- Talar body fracture associated with ankle fracture is very rare. Still, the malleolar fracture that allows adequate visualisation, anatomical reduction, and appropriate fracture xation can give us hope to reduce complications.

Vertical Fracture Monitoring by Multi-Rate Through-Barrier Diagnostics

Hydraulic fracturing has been demonstrated to be a cost-effective method of developing low-permeability heterogeneous clastic reservoirs with vertical wells. In the presence of a thin shale layer as a seal, monitoring effective fracture height becomes extremely important. The conventional approach of a single-regime production logging may be ineffective due to the complex geometry of fluid flow in the near-wellbore zone around the well. The paper describes the experience of the multi-rate through barrier diagnostics as a method of improving hydraulic fracturing evaluation. The standard way to diagnose the effectiveness of hydraulic fracturing is to log a survey under current operating conditions. In general, temperature and passive spectral acoustic measurements provide useful information on identifying the boundaries of fluid movement behind production casing; however, it is difficult to determine if flow occurs in the vertical hydraulic fracture or channeling through damaged cement in a single-regime survey. The multi-rate through-barrier diagnostics allow analyzing the flow dynamics of the wellbore-fracture-formation system under different flowing regimes, enabling a more accurate assessment of fluid movement in the near-wellbore environment within several meters. The paper includes the results of the multi-rate logging survey campaign in vertical water injection wells drilled in a low-permeability clastic reservoir. A proppant-based hydraulic fracturing of the target formation was carried out in the wells. The geological structure of the developed reservoir includes a thin shale layer (break) that separates the target oil-saturated interval from the overlying water bearing reservoir. In order for the operator to optimize future stimulation programs identification of effective hydraulic fracture height in reservoir regions with different shale thicknesses is crucial. The upper boundaries of the injected fluid movement behind the casing were determined based on the survey results. Analysis of the acoustic and temperature field dynamics helped more reliably evaluate the nature of the fluid movement behind the casing, whether flow happens in vertical fracture or cement channeling. This results in a more precise quantitative assessment of the injection profile in the targeted and untargeted reservoir units.

LONGITUDINAL FRACTURE INFLUENCE ON THE UNFOCUSED LATERAL LOGGING SOUNDING RESPONSES IN HIGH-RESISTIVITY DEPOSITS

The article considers the analysis of unfocused lateral logs (BKZ) simulated in three-dimensional media models with a vertical fracture. It was found that for the Tomsk region Upper Paleozoic deposits conditions the influence of a single thin fracture passing through the well axis on the signals is equivalent to the influence of the invaded low resistivity zone. On the practical data measured in the well of Archinskoe oil-gas-condensate field (Tomsk region) we discuss the possibilities of numerical data inversion for identifying oil-productive intervals.